How can I reset my Screen Time passcode?

If you do not know the screen time passcode, you can use your Apple ID and Password if that was used to set the passcode. Follow this support article and if that does not work, you will need to use the link in the article to contact Apple.

If you forgot your Screen Time passcode - Apple Support

What issue are you having resetting the passcode?

When setting up a screen time passcode, you have the option to use your Apple ID to reset it, did you choose this option?