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+# .env
+POSTGRES_USER - postgres user name
+POSTGRES_PASSWORD - postgres password
+POSTGRES_DB - database name
+POSTGRES_PORT - backend port number on docker network
+POSTGRES_HOST - backend docker container name
+
+BACKEND_PORT - backend port number on docker network
+BACKEND_HOST - backend docker container name
+
+DOMAIN - domain for certbot
+EMAIL - email for certbot