Hi,
Yes you can navigate to specific screen as per your requirement.
In the Powerapps URL at the end add &screenID=1 (Screen IDs you can define as your wish)
Within your Canvas app, App --> Onstart property enter the following formulae
Set(startScreen,Param("screenID")); //Read ScreenID Parameter
Switch(startScreen, "1", Navigate(Screen1),"2",Navigate(Screen2)); //Navigate to corresponding screen as per the ID
Hope this answers your question.
If it answers please mark it as verified.
Regards,
Pavan Kumar Garlapati