Invalid phone number for login to Microsoft Teams

[ChispitaMono]

Hi,

I am trying to setup Microsoft Teams for my daughter to do her guitar lessons online on her iPad.  I have downloaded the Teams app, but when I try to login it asks for a phone number to associate with the Microsoft apps.  When I enter her phone number it then tells me the number is invalid (which it is not).  

does anyone have any suggestions?

many thanks

[#2]

@ChispitaMono I am using it for personal use. Better to create a outlook.com account and sign in to Teams app. 

Also do you mind posting screenshot of error if the above doesnt work?

[#3]

I have the same problem. I tried to sign in using outllook acc but it's still requiring to add number.