If you have blocked someone by mistake and now you don't know how to unblock them, then read and follow the steps given below it will help you.

- Open your profile

- Click on three horizontal lines on the top right corner and then click on settings

- Click on Privacy & then click on blocked accounts

- You will find all the blocked accounts there and then click on unblock on the account which you want to unblock

If you get any problem then read this article:- https://getassist.net/block-someone-on-instagram/