why wont it let me update an app
I have an iPhone 7 and I’m trying to update an app but at the top it says “put Apple ID” but when I look at the user it doesn’t say my user it says my moms gmail user and when I put her Apple ID it didn’t work, and I tried her old gmail password and it didn’t work and then I tried her new gmail password but it didn’t work, I put my Apple ID password but it also didn’t work, what do I do?