Website: Facebook, NodeJS+ Express: The domain of this URL isn't included in the app's domain”

I have been trying to address this issue for two weeks but have been unable to solve the problem.

I am trying to utilize Facebook login on my website, but it keeps stating "Cannot load URL", telling me that I did not add in the domains/subdomains.

I made my website https instead of HTTP to cater to Facebook's new terms but that hasn't fixed the issue.

Please, help me with this if you are knowledgeable on this subject.