Yealink T48S Skype For Business Edition User Manual page 37

If you want to change to voice call verification method, do the following:
1)
2)
3)
Your phone will sign into Skype for Business Server successfully.
Passing MFA When Using Web Sign-in
To pass MFA when using Web Sign-in method via web user interface:
Using Web Sign-in method to sign into Skype for Business.
1.
For more information, refer to
Your web browser enters the verification screen.
Depend on the authentication method you select on the Skype for Business client:
2.
If you select Call me, your mobile phone will receive a call:
-
Answer the call and follow the voice prompt to complete authentication.
If you want to change to text verification method, do the following:
Tap Switch on the verification screen.
Select Voice call verification.
Answer the call and follow the voice prompt to complete authentication.
Web Sign-In on page 28.
Getting Started
35