To unblock someone in Roblox, first log into your account at www.roblox.com. Once logged in, click the gear icon located in the top right corner and select Settings.
Next, in the settings menu, find and click on Privacy from the left sidebar. This will open your privacy settings.
Scroll down until you see the Blocked Users section. Click on Show to reveal the list of users you have blocked.
Locate the user you wish to unblock. Click the Unblock button next to their name, and they will be unblocked.
If you have parental controls or two-factor authentication enabled, you might need to disable them temporarily to complete the unblocking process.