Its know to all that Facebook is one of the most used social media platforms. But it's not a piece of cake to get many engagements here. For that, you have to keep in mind some points. Here they are:-
> Target the proper audience.
> Use image videos to attract more audience
> Publish the post on popular hours
> Do not avoid conversation
> Show engagement
> Promote the advertising campaign on other platforms too
> Keep the focus on a trending topic
> Boost your post
You can follow them to boost up your campaign. I think it's also clear your doubt on " How to boost a post on Facebook?" too.