After iOs 14, there have been a lot of weird bugs surrounding the installation of apps from third parties. It started with when installing you would get an error saying you're unable to install, but now you're not able to install at all, because the app freezes as soon as you press the install button. I paid 20 euros for the + app for less revokes, but now it's completely wasted as I've not been able to install anything for the past 2 months.
You may already know about it but I've not been able to read any one else asking about this, and I think it's something that needs to be fixed right away, or else more updated about.