My I phone 8 is locked and I forgot the Passcode

OK, since you didn’t follow the instructions at the top of this page, here they are again, in more detail.

If your device has iOS 15.2 or later installed, you can reset it without a computer; check out this link→How to reset your iPhone, iPad, or iPod touch when you forgot your passcode - Apple Support. Otherwise you will need a computer:

See this Apple support link→If you forgot the passcode on your iPhone, or your iPhone is disabled - Apple Support

Or watch this companion video ⬇️

After restoring the phone using one of the methods above you can restore your most recent backup.

What was the result when you followed the guidance in the Related Article above your name on this page, that you were reading just before you posted here? If the Related Article doesn't answer your question please post back with more details about the issue and another user in this user-to-user forum will try to help.