Unfortunately you don’t provide a lot of information about what you did check in advance, so not sure how to help you here without telling you to simply ask your landlord for help.
Did you, for example, check that prepaid Mastercard/VISA cards are accepted there?
Probably it’s an old proprietary token system with a special card you need to load with tokens somewhere?
Most likely though since you said “germany” it only accepts german “girocards” perhaps and not Mastercard/VISA? This is the most probable explanation with the little information you provide.
In case you checked all that and it indeed accepts Mastercard/VISA, it’s highly likely it does not support online transactions needed with prepaid cards if your Revolut card isn’t accepted.
Only if it does indeed accept prepaid Mastercard/VISA you can use your Revolut card there and then if that doesn’t work you might want to contact the support or check your security settings in the App.
Otherwise you’re out of luck with Revolut card(s) here.