Database connection in 3.9

Hello everybody :slight_smile:
I am trying to update an application from 3.x to 3.9.
But I just can’t connect to the database.
It seems to be in the .env file but I cannot make it work.
I tried : export DATABASE_URL=“mysql://DB_name:DB_pwd@DB_address/${APP_NAME}?encoding=utf8&timezone=UTC&cacheMetadata=true&quoteIdentifiers=false&persistent=false”

I am not sure for APP_NAME.

And how do I configure a second database ?