Push Notifications for Major Browsers

I need a push notification system that supports these major browsers:
– Chrome
– Firefox
– OSX Safari
– Edge
– Internet Explorer
– Android Chrome
– IOS Safari

The goal is for my Python scripts to send push notifications to our users via the requests library. I do not want to use an online service. I have a database to store the subscriptions and plan on sending dynamic content to varying subsets of users serval times throughout the day. I currently have Google’s Web Push Notifications working fine, however Internet Explorer, Safari, and Edge do not function as expected. I followed a few tutorials to get to where I am so I am not completely knowledgeable of what is required to achieve what I am asking for. I assume this will be mostly JavaScript (service workers) with a potential pythonic interface.

You must be able to use your own keys for development and I will be using my own for the release version.