Can I sign into my apple id on the computer and change my passcode?

Sorry, but no.

Are you saying that you forgot your passcode?

f your iPhone is running iOS 15.2 or higher........you can use the instructions linked just below:

How to reset your iPhone, iPad, or iPod touch when you forgot your passcode - Apple Support

If your iPhone is not running iOS 15.2 or higher........please use the instructions linked below, but note that you must use a PC or Mac.

If you forgot your iPhone passcode - Apple Support

If you have a backup of the phone, you can use the backup to restore the data on the phone during the new setup.

Sorry, there is no option to do that. If you know the current passcode, you can change it on the phone itself at Settings > Face ID & Passcode. If you don't know the current passcode or if you are locked out, you can use the following instructions: How to remove your iPhone, iPad, or iPod touch passcode without a computer - Apple Support

If that option is not available, you will need to use a computer. See: If you forgot your iPhone passcode - Apple Support