If you're on Damus TestFlight, it's probably full though, you can enable Zaps by going to this website. https://nostrscript.suhailsaqan.com/
Apple rugged iOS users, making all devs besides the Current app, remove Zaps. Fuck Apple. You can Zap via ZapplePay. It's a workaround. https://ZapplePay.com
If you're on Damus TestFlight, it's probably full though, you can enable Zaps by going to this website. https://nostrscript.suhailsaqan.com/
Again, another fuck you Apple work around.