Want to insert "FirstName" column in AspNetUsers table in asp.net webform application

Created Asp.net webform application and want to add FirstName field into AspNetUsers table. I followed some articles but no luck. I tried the following and getting this error.

Enable-Migrations System.ArgumentException: The parameter is incorrect. (Exception from HRESULT: 0x80070057 (E_INVALIDARG)) Server stack trace: at EnvDTE.Properties.Item(Object index) at System.Runtime.Remoting.Messaging.StackBuilderSink._PrivateProcessMessage(IntPtr md, Object[] args, Object server, Object[]& outArgs) at System.Runtime.Remoting.Messaging.StackBuilderSink.SyncProcessMessage(IMessage msg) Exception rethrown at [0]: at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg) at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type) at EnvDTE.Properties.Item(Object index) at System.Data.Entity.Migrations.Extensions.ProjectExtensions.GetPropertyValue[T](Project project, String propertyName) at System.Data.Entity.Migrations.MigrationsDomainCommand.GetFacade(String configurationTypeName, Boolean useContextWorkingDirectory) at System.Data.Entity.Migrations.EnableMigrationsCommand.FindContextToEnable(String contextTypeName) at System.Data.Entity.Migrations.EnableMigrationsCommand.<>c__DisplayClass2.<.ctor>b__0() at System.Data.Entity.Migrations.MigrationsDomainCommand.Execute(Action command) The parameter is incorrect. (Exception from HRESULT: 0x80070057 (E_INVALIDARG))

Any help is highly appreciated.