Buy Xbox Gamepass Ultimate from Phone

Hello everyone, I have a Question, I want to buy Xbox Gamepass from the Phone, using the Xbox Gamepass application, because I have $2 on Google Pay Billing, but when I try to buy from the cellphone, pressing the central button that makes you go to the passes, It just let's me see it and I can't buy it from there, it's just like Labels of price and the data, I can't find how to somehow buy it from the app.

Thx for reading, solutions will be appreciated.

:)