MySql Connection String localhost

I need to compose the connection string for my WebApiCore application now running on Linux.

I tried something like this:

server=localhost;uid=User;pwd=Password;database=Database;

but I always get this error:

System.Data.SqlClient.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

What am I doing wrong or what am I missing?

I think the problem lays in localhost keyword, but I can't figure out what to use

Thanks for the help

Looks like your question is in regards to MySQL, but the client is attempting to connect to a SQL Server database.