Unable to download apps on iPhone due to 'restrictions set for this device'

I have a family set up iPhone fifteen, and it won't let me install pokemon to due to "Due to restrictions set for this device, this app cannot be downloaded". I have the exact same issue for all other appsI try to download on the phone. In settings, I checked, installing apps from app store and itunes store is set to allow. Any ideas to fix it.

[Re-Titled by Moderator]