Facebook login is not working

Make sure you have followed steps 18 and 19 from the link https://support.heateor.com/how-to-get-facebook-app-id/

I’ve checked on steps 18 and 19 already, but it still doesn’t work though

Can I have the URL of the website?

Here is the URL of website

https://narathong.com/

The original Javascript code on click of the social login icon has been altered. See https://imgur.com/HYKoKj0. That’s why the icon is not responding.
You can try keeping only this plugin active just to check if this makes any difference. Then activate other plugins one-by-one to check which one is altering the code. Once you detect that plugin, we can work on the resolution.