Logging into my account

Why is it so dang hard to log into T-MOBILE app without a T-Mobile phone number.. I think they need to go back to the drawing board and give it another good ole college try.. like for real all I wanted to do is login to activate my sim card to activate my phon3s.. but no T-Mobile has nothing better to do thwn spin and throw customers like crazy.. had anyone in this community cracked this conundrum yet.. because all I see when you Google this problem is a whole lot of sad emoji faces plrase someone help me... Dazed&Confused.. in Fla.