Firebase from Magento and via Amasty push notification module

We have installed an Amasty push notification module in out magento 2.4.3 p1 server.
We were told it should be able to push to mobile app notifications but it does not.

We have investigated the module and it should be pretty straight forward to do the job. The magento developer we have has not integrated with firebase previously so he suggests we get an experenced PHP+Firebase integrator to do the job.

Work to do:
1. create API for mobile app to forward the FCM ID to the magento server. Then we can send the message via the amasty app
2. create firebase connection from the magento server to firebase via PHP, found link as suggestion: https://www.youtube.com/watch?v=yfha-LFRM-I (pretty complete) OR https://www.howtogeek.com/devops/how-to-send-mobile-push-notifications-with-php-and-firebase/
3. Here you can use the IDs Amasty stores in the table already.
4. You use a couple of key values the Firebase is using to send hidden SKUs and campaigns.

To solve this we need to implement a connection to the firebase and make it work from the Amasty scheduler and to some specific devices.

PREREQUISITE:
1. you must have done this previously
2. you can install magento on a server even if it is a mac, pc or linux machine you are working on (last one could not do this so he had to stop). The code is currently running on a Ubuntu 18 server.
3. You have done php connection to the firebase.


Your skills:
- magento 2.4.3 p1 minimum
- php 7.4 minimum
- firebase
- magento to firebase connection

PS! please read all again and understand every word of the advert i write. I am not interested in people who are not experienced in installing magento and use github. We do not work on the servers, we are professionals, not some home hacker.
I usually install magento in 1 hour with composer and I can do it faster too on Linux machines.
So:
1. install standard magento and DB (1.8Gb)
2. git init
3. git remote add origin
4. git pull origin master
5. compile
6. done