Facebook contest / contest

Hello,
SEMrush

I want to run a Facebook contest / contest to help increase my "likes" or my page.

I would like to know if I can participate in a competition that involves users who post a comment in a publication.

Also, I wanted to know if I can promote this contest on another website with something like:

"Go to our Facebook page to participate in our competition, all you need to do is tell us your favorite ___"

Thank you