Home Assistant for iOS supports opening from other apps via URL.
Query parameters are passed as a dictionary in the call.
This allows you to update the frontend page location via a deeplink. This requires version 2021.3 or later.
For example: if you had a dashboard at
/lovelace/webcams you can use
homeassistant://navigate/lovelace/webcams to launch the app there.
You can create an event trigger and fire the event.