To change the authentication methods on your account, please closely follow the instructions listed below:
You will see 4 options, as shown below:

If you know your account password, select the second option, the UPDATE option, to update your recovery information and follow the prompt on that page.
Please select "I want to set up a different method" if you see the Microsoft Authenticator App authentication option as shown below:

You may also see the page shown below, please select "Add sign-in method" or "Change" next to the contact method you want to update:

Select "Phone" to add your phone number as shown below or select "Email" to add a personal email if preferred.

On the next screen add your personal phone number or email and select "Text me a code" and follow the prompt on that page.
You may repeat this process to change or add more authentication methods.
Thank you,
LAFS IMT Support Team
After following the steps above, do you still need assistance?