iphone ask for my old passcode which i have forgotten

Hello hhuib123,

Thank you for using Apple Support Communities! I see that you're prompted to enter the passcode from your previous iPhone, which you've forgotten. I would be happy to help provide steps to take next.

While it's not possible to reset this passcode, you can tap on the "Forgot iPhone Passcode?" option, which will then walk you through resetting your end-to-end encrypted data stored in iCloud. This will allow you to continue signing in to your iCloud account on this iPhone after.

The "End-to-end encrypted data" section in the resource below provides more information about this process:

iCloud security overview - Apple Support

Take care.