Unfortunately from today you can no longer login to OpenStreetMap.org using a Facebook login. Facebook introduced new requirements to use the feature, but despite us submitting the required documents & reaching out to them they were unable to verify us before the deadline.
If you are one of the roughly 500k users affected by this you can use the password reset feature to set a login password https://www.openstreetmap.org/user/forgot-password We will continue to try resolve the issue with Facebook/Meta.
Facebook logins to OpenStreetMap.org are enabled and working again. Thank you to all those who helped resolve the issue. Happy Mapping.