Locked my iPhone 15 plus
Can I unlock this with my iPad?
Question marked as
No, you will need a Mac or PC if your forgot your passcode to reset the iPhone using Apple Support document linked just below
If you forgot your iPhone passcode - Apple Support
If you want to try to reset the passcode without using a computer, please refer to this Apple Support document.
If you see an iPhone or iPad unavailable message or Security Lockout screen - Apple Support