Push notifications problem

With the app from the Play Store the push notifications work correctly, but if I download the app from the Traccar download site the notifications do not work and in the same way if I download the source code and create the app in the same way the push notifications do not work . You can support me to see why this is.

Thank you.

The APK from the website doesn't have Google dependencies.

As for source code, there are two flavors:

• Regular (no Google libraries -> no push)
• Google (with Google libraries -> push enabled)

Thanks for the reply.

Could you explain to me how it is done from the source code with:
• Google (with Google libraries -> push enabled)

Build google flavor of the app.