I can’t remember my parental control password

It seems you have forgot your screen time passcode, we’ll have to reset it then, follow along with these steps:

On your iPhone:

• Go to Settings > Screen Time > Tap Change Screen Time Passcode > Tap it again > Tap Forgot Passcode? > Enter your Apple ID and password > Enter your new password.

If you still have issues resetting your Screen Time passcode, contact Apple Support.

For more information: If you forgot your Screen Time passcode - Apple Support

When setting up the Screen Time Passcode, you are given an option to use your Apple ID in case you forget it. If you did not use that option, you will not be able to reset it using your Apple ID as has been advised.

You will then be stuck with contacting Apple directly and will likely be advised to factory reset your device. Before you do that you will want to save any data that you do not want to lose, since if you restored your backup, it will only bring back the screen time passcode that you do not know. Apple does not know it either.

Contact Apple for support and service - Apple Support

See this article.

If you forgot your Screen Time passcode - Apple Support