upload as much content related to that video on your page
1 post per hour/2 hours is ok
edit the description to a shortened link that leads to a product regarding that video if your audience is tier 1 or you think they will purchase
just not clickbait stuff
or comment the shortened link product
or comment another video similar to that one
with the caption Because you like (cats) here's another cute video of 2 kitten playing
if your page is less than 100k invite those who have interacted
and since its going viral if it doesnt break fb page terms + advertising TOS
if you have the budget and know 1 or 2 things about ads you can sponsor that video/boost
