In LINE app, go to More > Settings and tap on Accounts.
When you see the Facebook logo, tap on the Link button. You will be asked to
login to your Facebook account. Accept all permissions required to link
Facebook to the LINE app.
When you see that the Link option is now changed to Unlink, proceed to
uninstall your LINE app from your device.
Then, reinstall it. Here are the links for Android and iOS. Once reinstalled, open
LINE app.
Tap on LINE User Login and then tap on Facebook (login again if you have
to).
If they ask you to enter a PIN number and you don’t have one, just type in the
last 4 digits of the previous phone number attached to your LINE account.
