Hello @amiableCDN , welcome to the community.Fido xtra is part of the Fido postpaid service, except for the basic plans. If you don't want to receive notifications from the app about Fido Xtra, you could turn off the notifications in the app, or if you don't wan't to see at all in your app, you would have to uninstall the Fido app. The Fido app provides quick and easy access to your account information with links to support for any questions you may have.
May I ask, what part of the xtra service do you want to stop? Read here for more information on Fido Xtra.
I hope that answers your question. cheers