The issue is that your data base is not set up. Make sure you can read it via your phpMyAdmin app (or whatever app you use to setup and view your database). For the master_2019.2 version, the database information is in the config/custom.config.php file. For the master_2020 version it is in the config/custom.config.ini file. If it is the master_2020 version you are loading, it is possible that the databasePassword value needs to enclosed in quotes. Once this information is properly set up, the application will proceed to the update screen.