I came across this warning scene before. This time I clicked Install anyway, as you recommend. 
Discussion
Installed Testflght version of Damus.
Still can’t get a Lightning ⚡️ zap icon to display on peep’s Notes so I can Zap them on Damus. And the ⚡️that shows up under the sunrise photograph doesn’t let me click it.
Thanks for trying to help me. Sorry for wasting your time. 
Set up Alby in Wallet