First of all locate your directory by click on the top left corner File section and selecting open folder. When you finaly located your directory create two text files and name them accordingly to your coding enviroment inside the '.env.' '.env.'. Usually files are named 'test' and 'development'. When you created the files with assinged names write this code accordingly to which data base you are targeting. "PGDATABASE=<DATA_BASE_NAME>".
Do not forget to install the Dotenv dependency otherwise it will not work.