Hello,
Which template are you using? That way we can advise you which files to possibly edit etc.
I have written a blog post on how to do this. Please have a look and if you have further questions, please ask again.
https://stoned.io/web-development/hugo/Embedding-Facebook-In-A-Hugo-Template/
I’m still working on it to make it better. I’m a new author. 
Hope this helps.
Cheers,
Sincerely,
Hash