How to implement SSL Pinning?

Question

Java

Google didn't really give any results, mostly some ways to bypass SSL Pinning.
How to implement SSL Pinning in your Android app and send GET/POST requests with it? Preferably without using the NDK.
Does the signature of the application itself act as a certificate or is a ready-made certificate implemented?
Then this certificate needs to be implemented into the domain as a regular SSL certificate?
If the application signature is used as a certificate, then it turns out that when uploading to Google Play, it is impossible to sign the application with their signature to protect mine?

Answer 1

Maybe, as it is written in the official documentation ?