How to change the password on a Apple 15 Pro Max without iTunes or computer mainly reset it

There's a difference between between a passCODE which is a four or six digit code used to unlock a mobile device after you turn it on (or other services on a mobile device), and a passWORD which is what is used to log into your Apple ID account which may be required in resetting a forgotten passCODE. I am not clear as to which you are referring.

Read the Apple Support document for what to do if you forgot the passCODE on an iPhone or iPad. Click here then select your device type if necessary --> If you forgot your iPhone passcode, use your Mac or PC to reset it - Apple Support - Which one you can use depends upon your equipment configuration.

Also:

If you forgot your iPad passcode, use your Mac or PC to reset it - Apple Support

Seek assistance at an Apple Store.