Integration of Push Service into existing PWA

I am seeking a qualified individual that can get us connected to be able to send push notifications from our existing Progressive Web App. We have already deployed a [login to view URL] and [login to view URL] with cache strategies these all load fantastically and we get prompts for load to home screen, full screen mode, are able to use the devices camera & location, as well as local storage (data/file). We would now like to blend in notifications, but are having issues with the third party service worker. We need to maintain what is currently been achieved and add the notifications service worker as an import or combined in one file. Thus far our trials have been with OneSignal, but I am open to other options based on capabilities and cost. This is an extremely low volume notification list and frequency. -Help us determine the best push service. -Add in service worker as an import or combined in one file for push notifications, maintain what is currently been achieved - Create sample code that would capture the registrants ID, match it with a login and save to a DB for individual message send later. - Create sample code to send messages to an individual, a group or all subscribers.