You cannot receive a push notification directly from Teams/ACS, but you can get a webhook notification sent to your service, which can in turn send the push notification to your app.
You can use Graph API to subscribe to receive webhook notifications for various events related to an online meeting (started, participant join/leave, end).
https://learn.microsoft.com/en-us/graph/webhooks?view=graph-rest-1.0
https://learn.microsoft.com/en-us/graph/api/subscription-post-subscriptions?view=graph-rest-beta&tabs=http