My passcode

if you forgot your passcode, you will be erasing the iPhone/iPad. You will have to rely on your latest backup and information stored in iCloud

If you forgot your iPhone passcode - Apple Support

If you forgot your iPad passcode - Apple Support

When forgetting your iPad passcode, you will need to erase the iPad yes

There are 2 ways of doing that:

If you're running iPadOS 15.2 or later you can do this without using a computer

How to remove your iPhone, iPad, or iPod touch passcode without a computer - Apple Support

If you're running an earlier version of iPadOS you will need to use a computer or Mac to do this, see this link and follow the instructions

How to remove your iPhone, iPad, or iPod touch passcode without a computer - Apple Support