Login page works in visual studio, not in IIS

This may seem like a duplicate question but the answers provided in the other posts did not help.

I am making a C# ASP.NET website, currently it works fine when testing in the Visual Studio IDE. The site uses the default login controls that are created when you create a new asp.net web application. The problem is, when loaded through the IIS (going to the hosting computers IP address from another computer) every page loads, but the login part fails. Here is the error screen:

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.Data.SqlClient.SqlException: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 50 - Local Database Runtime error occurred. Cannot create an automatic instance. See the Windows Application event log for error details. )

Stack Trace:

[SqlException (0x80131904): A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 50 - Local Database Runtime error occurred. Cannot create an automatic instance. See the Windows Application event log for error details.
)]
   System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, Object providerInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString userConnectionOptions, SessionData reconnectSessionData, DbConnectionPool pool, String accessToken, Boolean applyTransientFaultHandling) +1394
   System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions) +1120
   System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnectionPool pool, DbConnection owningObject, DbConnectionOptions options, DbConnectionPoolKey poolKey, DbConnectionOptions userOptions) +70
   System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection) +910
   System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection) +114
   System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal& connection) +1637
   System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal& connection) +117
   System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal& connection) +267
   System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions) +318
   System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource`1 retry) +211
   System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry) +393
   System.Data.SqlClient.SqlConnection.Open() +122
   System.Data.Entity.Infrastructure.Interception.InternalDispatcher`1.Dispatch(TTarget target, Action`2 operation, TInterceptionContext interceptionContext, Action`3 executing, Action`3 executed) +104
   System.Data.Entity.Infrastructure.Interception.DbConnectionDispatcher.Open(DbConnection connection, DbInterceptionContext interceptionContext) +509
   System.Data.Entity.SqlServer.<>c__DisplayClass33.<UsingConnection>b__32() +567
   System.Data.Entity.SqlServer.<>c__DisplayClass1.<Execute>b__0() +15
   System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute(Func`1 operation) +238
   System.Data.Entity.SqlServer.SqlProviderServices.UsingMasterConnection(DbConnection sqlConnection, Action`1 act) +916
   System.Data.Entity.SqlServer.SqlProviderServices.CreateDatabaseFromScript(Nullable`1 commandTimeout, DbConnection sqlConnection, String createDatabaseScript) +117
   System.Data.Entity.SqlServer.SqlProviderServices.DbCreateDatabase(DbConnection connection, Nullable`1 commandTimeout, StoreItemCollection storeItemCollection) +212
   System.Data.Entity.Migrations.Utilities.DatabaseCreator.Create(DbConnection connection) +135
   System.Data.Entity.Migrations.DbMigrator.EnsureDatabaseExists(Action mustSucceedToKeepDatabase) +175
   System.Data.Entity.Migrations.DbMigrator.Update(String targetMigration) +116
   System.Data.Entity.Internal.DatabaseCreator.CreateDatabase(InternalContext internalContext, Func`3 createMigrator, ObjectContext objectContext) +121
   System.Data.Entity.Database.Create(DatabaseExistenceState existenceState) +293
   System.Data.Entity.CreateDatabaseIfNotExists`1.InitializeDatabase(TContext context) +187
   System.Data.Entity.Internal.InternalContext.PerformInitializationAction(Action action) +72
   System.Data.Entity.Internal.InternalContext.PerformDatabaseInitialization() +483
   System.Data.Entity.Internal.RetryAction`1.PerformAction(TInput input) +177
   System.Data.Entity.Internal.LazyInternalContext.InitializeDatabaseAction(Action`1 action) +274
   System.Data.Entity.Internal.InternalContext.GetEntitySetAndBaseTypeForType(Type entityType) +38
   System.Data.Entity.Internal.Linq.InternalSet`1.Initialize() +77
   System.Data.Entity.Internal.Linq.InternalSet`1.get_InternalContext() +21
   System.Data.Entity.Infrastructure.DbQuery`1.System.Linq.IQueryable.get_Provider() +59
   System.Data.Entity.QueryableExtensions.FirstOrDefaultAsync(IQueryable`1 source, Expression`1 predicate, CancellationToken cancellationToken) +208
   System.Data.Entity.QueryableExtensions.FirstOrDefaultAsync(IQueryable`1 source, Expression`1 predicate) +172
   Microsoft.AspNet.Identity.EntityFramework.<GetUserAggregateAsync>d__6c.MoveNext() +502
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +13891908
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +61
   Microsoft.AspNet.Identity.CultureAwaiter`1.GetResult() +48
   Microsoft.AspNet.Identity.<FindAsync>d__12.MoveNext() +357
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +13891908
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +61
   Microsoft.AspNet.Identity.AsyncHelper.RunSync(Func`1 func) +348
   Account_Login.LogIn(Object sender, EventArgs e) +119
   System.Web.UI.WebControls.Button.OnClick(EventArgs e) +11762637
   System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +150
   System.Web.UI.<ProcessRequestMainAsync>d__523.MoveNext() +7798

Here is the connection string in the web.config file

<connectionStrings>
    <add name="DefaultConnection" connectionString="Data Source=(LocalDb)\MSSQLLocalDB;Initial Catalog=aspnet-nes-a6ab9e95-1ec8-4eee-af0f-bc33406759d6;AttachDbFilename=|DataDirectory|\aspnet-nes-a6ab9e95-1ec8-4eee-af0f-bc33406759d6.mdf;Integrated Security=SSPI" providerName="System.Data.SqlClient" />
  </connectionStrings>

Things I have tried:

• added iusr(aspnet user not found) to the list of users in SQL management console
• made sure the account is loaded in IIS application pool
• Checked and verified the SQL service is running
• Changed the IIS site connection string to the string provided during SQL Express install

So far no matter what change I make it is the same error message. Also in case it matters I am using Visual Studio community 2017 and SQL express server 2016

Do not use Local Db in your connection string. Instead, use SQL EXPRESS Server. Example:-

  <connectionStrings>
    <add name="DefaultConnection" connectionString="Data Source=(local)\SQLEXPRESS;Initial Catalog=InstituteManagementDB;Persist Security Info=False" providerName="System.Data.SqlClient" />
  </connectionStrings>

Refer here to find Format for Specifying the Name of SQL Server

https://docs.microsoft.com/en-us/sql/database-engine/configure-windows/logging-in-to-sql-server?view=sql-server-ver15