test db su rpi4 - in vpn su instance-1
https://opensource.com/article/17/10/set-postgres-database-your-raspberry-pi
https://blog.logrocket.com/nodejs-expressjs-postgresql-crud-rest-api-example/#whatisnodepostgres
https://www.twilio.com/blog/working-with-environment-variables-in-node-js-html