build simple app with push notifications

I need app with one page only , once user installs , will need to have token unless cannot continue only
first time and also will ask them which channel(s) they want to subscribe to and they can subscribe to any number of channels
the list of channels will be pulled from an api (already exists no development except calling the api and getting list of channels)

the app need to receive push notifications from OneSignal for example or (you can recommend any other service but this service need to have api that we will call from server side (server side is out of the scope of this))
however you will be responsible to test this from Postman for example

once the notification come , and user click it it needs to open all details of the notifications and maybe images and links in the app (also need to show the channel that received this notification if subscribed to more than one channel)


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your responsibility
- Design and develop the App (Android and iOS)
- App should not run first time only except the user has predefined token you can use now "ALLOWME" for all users
- test that it is receiving push notifications and showing them appropriately
- calling the channels api to get list of available channelSubs assume the results of this api will be
[
{ channelId:1, channelMain:'Wahtsoever Organization', channelSub:'Group 1'},
.....
]
- the user can subscribe to any line of this channels
- fully pushing the app to google play and apple app store is your responsibility
you can create new common email that we can use for both