Blocking Apps
Is there a way for me to block certain app from being downloaded on my phone using screen time or something of that sort?
iPhone 11, iOS 14
Probably not, due to the Catch-22 of having to identify the program in order to block it. Without knowing what kind of program, it is, nor how it comes to be installed on your phone without your consent, it is a bit difficult to offer a creative solution to your problem.
What you should be able to do is install the app but completely disable it. Turn off all notifications for the program, disable its access to all iPhone services, like Camera, Photos, Microphone, Location Services, etc. Everything disabled. Then, through Screen Time, prohibit use of the program by anyone 24 hours a day. Good luck.