How to make user access to google cloud sql database?

Question

Google Cloud Platform

I have a smartphone app, I use Firebase in it, registration via gmail, facebook, etc. I need a sql database, I decided to use google cloud having difficulty accessing it. I managed to connect to it from my PC only by adding my local ip to Public IP. The documentation says you need to use Cloud SQL Auth proxy.
Can someone write step by step what needs to be done so that users of my application have access to the database, and it is safe?