@Juanjo Prado Esteban
Thank you for posting this in Microsoft Q&A.
As I understand you are unable to access Azure services as you have changed the phone on which you had initially set up your authenticator app.
Since you have the new phone currently you are unable to access any of the Azure services because you are unable to get a code on your phone.
To resolve this issue, you will have to contact Global admin of your tenant. They will set your account for you to re-register your account.
If you don't know who Global admin for your tenant is you can perform below steps,
I would suggest you ask one of your colleagues to perform below steps and share the global admin details with you so that you can contact admin and get your MFA registered.
- Open Windows PowerShell as administrator.
- Run command “Install-Module azuread”
- Once installed you can run command “Connect-AzureAD” and enter user credentials once it asks for.
- Once you login, you can run command “Get-AzureADDirectoryRole”.
- From the output you can copy the object ID of Global administrator
- Run command “Get-AzureADDirectoryRoleMember -ObjectId "Paste the object ID of global admin that was copied earlier"
- You will get the list of users with global admin role assigned.
Now you can contact any global admin from the list and ask him to perform below steps to reset your MFA so that you can re-register for authenticator app.
- Admin has to login to Azure portal and access Azure active directory.
- Once done they have to go to users blade on the left.
- Click on the user account which has been locked out.
- Click on Authentication methods and click on “Require re-register multifactor authentication”.
- Now when you try to login to Azure services it will prompt you to register for MFA again.
Let me know if you have any questions.
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