An App Password is a special password you create that allows apps that can't use two-step verification to access your account. It takes just a few minutes to do.
To get an App Password, follow Microsoft's Guide. Skip the first section, and start at the next section titled "To Create another app password". When you create the password, give it a meaningful name in case you ever need to delete it (such as if you lose your device).
For MiCollab: you'll need to paste the app password into the Exchange Password when asked for it
For Mobile Devices: at step 7, instead of copying the password to your clipboard you will need to type it in to your app when it asks for your password.
Important! App passwords bypass two-step verification and should be used rarely and with great caution. Do not ever write down, store, or share this password. Always create a new password when needed and delete unneeded ones at the same time.