Backing up Microsoft Authenticator
For those of you using Microsoft Authenticator, there's a key step you should take to avoid pain at some point. That is, back up your profile. This would also apply to other apps such as Authy or Google Authenticator; each has similar methods.
If you lose or reset your phone, that data is only on your phone. If you have multifactor set up to use just the Authenticator App, and don't have any other backup codes, you might be locked out of your account permanently. This would really depend on the application in question, but if it's a cloud service that isn't administered by your IT department, you could be stuck.
The backup should be done with an account that you are confident is also very secure, with a separate MFA, such as text message, on it.
Review the link below for the official documentation from Microsoft, split into Android and iOS (iPhone/iPad) instructions.