Keeps asking me to verify my password for downloading apps

I’ve been having trouble downloading certain apps like I was able to download the Nike app without it asking me to verify but I haven’t been able to download the gmail app. Every time I try to download gmail it ask me to verify my password to look at my billing information, but once I look at it an click done the app isn’t even downloaded and it asks me the same thing again. Then it becomes this endless cycle of me getting nowhere with getting the app.