Forgot iPhone password

Is it the 6-digit Pass Code or the Apple ID password that you need?

If you’ve forgotten your iPhone’s passcode, you’ll have to reset (erase) it and restore from a backup.

For that you WILL need your AppleID credentials and proceed as follows:

How to reset your iPhone, iPad or iPod touch if you've forgotten your passcode – Apple Support (AU)

Note: If your iOS version is prior to 15.2, you’ll ADDITIONALLY need a cable and computer to complete the supplemental instructions linked near the bottom of the article.