Hi AIDAN, I am Paulo and I'd like to help.
Check "Sign out of the iPhone/iPad (iOS) App" in the link below and see if it helps
https://www.itechguides.com/how-to-sign-out-of-...
(Disclaimer: This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.)