Select Settings & privacy , then click Settings .
You will see a list titled "Block users." Next to the person you want to unblock, tap the Unblock button.
If you’ve had a change of heart, unblocking someone is very easy—though it comes with a few important rules you need to know first.
Blocking someone on Facebook is a great way to take a break from a toxic connection or stop unwanted harassment. But sometimes, feelings change, arguments fade, or you simply miss seeing their updates.
Click your profile picture in the top-right corner.
Scroll all the way down to the Audience and Visibility section.