1) Sign in to the corresponding Facebook account that you want to disconnect from Messenger in the Facebook app.
2) Tap the menu option (the three-line icons)
3) Navigate to Settings & Privacy > Settings by scrolling down.
4) Go to Security and Login.
5) Then you will see the “Where you have logged in” section.
In this section, you will see all the devices on which you have logged in.
6) Go to the device and log out.
