Could not resolve host '(localdb)' on Visu

Question

Developing an Asp.Net web Api working with SQL. I'm stuck at debugging app on my Mac. When calling methods, working with db, app returns instead this error: System.Net.Sockets.SocketException Could not resolve host '(localdb)'

Feels like a mistake is somewhere in this line (according to other answers): Web.config file

<connectionStrings>
    <add name="DefaultConnection" connectionString="Data Source=(localdb)\MSSQLLocalDB; MultipleActiveResultSets=True; AttachDbFilename=|DataDirectory|MyDatabaseContext-12.mdf" providerName="System.Data.SqlClient" />
  </connectionStrings>

This app works perfectly fine in VS for Windows. Any ideas?

Update: I have an sql server in azure, so I have a connection string. Any way to make it used instead of local?