Facebook's API doesn't allow hashtags to be used as a source for social feeds.
Due to Facebook's restrictions, services like Juicer cannot search for or collect posts based on hashtags. This means you cannot create a Juicer feed using Facebook hashtags as a source.
If you have a Facebook source already listed in your "Social Media Sources" panel on Juicer, you can manually add posts from other users. Simply click the source in the panel, select "Add post manually", and paste in the Facebook post's URL.
Keep in mind that this manual method rarely works with posts from personal Facebook accounts because of privacy restrictions. It's not a reliable solution for adding Facebook hashtag posts, and Juicer cannot guarantee successful manual post additions.
If you still want to try adding Facebook posts manually, connect your personal Facebook account through the Connected Social Accounts page first. This gives you the best chance of success.