A user, Pravi, reports that Facebook’s debugger returns a 403 error for their privacy policy URL, despite the site being accessible. The issue is clarified by Falco, who explains that the original URL (/t/privacy-policy) is a private staff-only page, which Facebook cannot access. The solution is to use the public URL (/privacy), which is accessible to all users. Pravi acknowledges the explanation and thanks Falco for the clarification Pravi, Falco, Falco.
Hello guys!
Facebook give below mentioned error when trying to update the Privacy Policy in app settings..
You must submit a valid Privacy Policy URL in order to be compliant with
Facebook Platform. Request failed with error: Bad Response Code: URL
returned a bad HTTP response code.
Facebook debugger gives a 403 error only for privacy policy url. The site is working fine. All url are fine with facebook debugger, except privacy policy url. Any Idea guys ??
You need to log in to see that topic.
It requires that you be logged in to read it. I suspect Facebook thinks that you should be able to read the policy before agreeing to it. 
Use the special URL: https://engineersasylum.com/privacy
Thank you very much @Falco
It worked.. But what exactly was the problem ??
https://engineersasylum.com/t/privacy-policy is the topic which is the source of your privacy policy. It’s meant for staff (admin & moderators) only, it’s where you go to edit it. You can see on that page that the category is staff and there is lock on the category name. It’s private.
https://engineersasylum.com/privacy is the public link for it, like the ones in the hamburguer menu, like /faq and others.
Now I get it. Thank you very much.
Regards