How do I recover my forgotten password for a Windows PC connected to an Apple Account?

Sorry, your question does not make sense.

Windows PCs cannot be tied to an Apple Account beyond the iCloud for Windows app, and that has no bearing on how you log in to the PC.

If you forgot your login and your PC is using an Apple email as the Microsoft Account, the Apple account side has no bearing there.

https://support.microsoft.com/en-us/windows/change-or-reset-your-password-in-windows-8271d17c-9f9e-443f-835a-8318c8f68b9c

Question's clear as mud, but the gist is this: if you've signed into Microsoft services from macOS or an iThing, your Keychain might have it. The same holds trie if the device you touch Microsoft with is a Google thing; the Google Password Manager would have it. If, however, you skipped saving the password, it's a long road getting it reset. An email address registered with Microsoft must be active and accessible to proceed. They're either going to ask a ton of questions or send a bunch of codes to make sure it's a human what wants to get your credentials back. If you forgot or lost access to any address or number previously provided, you may be out of luck.

Nate