First time encountering such an inconvenient point-earning app

I saved up 1000 points and exchanged them for an au PAY gift code, but I can't copy the prepaid number. When I tap the code confirmation screen, it redirects me to the au PAY app download screen (even though I already have it downloaded). Of course, it's not auto-filled either. I can't copy it even by long-pressing. So, I had to painstakingly type it in manually. Earning points is also inefficient, so I absolutely cannot recommend this app. There was a "Taiku" thing, but how are you supposed to play that for 30 minutes?