I use a 3rd party password manager that has a Firefox browser extension. Using usernames and passwords is no problem. But for sites that I have passkeys saved for, Firefox tries to intercept the passkey request and validate the request on it's own. If I go into about:config and set security.webauthn.enable_macos_passkeys to False, the passkey request is just not accepted at all and the login request errors out. I need the browser to be able to pass these passkey requests to my extension based password manager, not to be interpreted by Firefox itself. The requested functionality works fine in Chrome and Chromium variants such as Edge and Brave, btw.