I need to reset my iphone7 passcode

OOPS, misread. To reset your passcode go to Settings/Touch ID & Passcode, enter your passcode, and then change passcode.

If the phone is locked or disabled you can’t reset the passcode, you can only restore it—>If you forgot the passcode on your iPhone, or your iPhone is disabled - Apple Support, then restore your most recent backup.

Reset as in you know what it is now and you want to change it, or as in, you forgot your passcode?

If the latter, follow the instructions here: If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled