This article explains how to change the Outlook email signature on your iPhone or iPad to something other than the default "Get Outlook for iOS" message. For example, add contact information, a quote, or other information. Instructions apply to the Outlook mobile app for iOS 12 and later.
How to Install an Email Signature in Outlook on iOS (iPhone & iPad)
The Outlook mobile app for iOS supports Microsoft and non-Microsoft email accounts like Gmail and Yahoo. You can use these instructions to change your Outlook, Gmail, Yahoo, and other email signatures, as long as the account is listed in the Outlook app.
To change your email signature in the Outlook app and create a different signature for each email account, follow these steps:
Open the Outlook app and tap your profile icon in the upper left corner. On older iOS versions, tap the three-line menu.