baby not crawling. how to help?

during tummy time my son will kick his legs like he’s trying to crawl, but in the air not against the floor. he’ll push up on his arms, then let go again and kick his legs. he won’t do both together, so is there any way to help him? he has the movements down just not the coordination.

he does this while reaching for toys and everything. so i think he is trying to move. does it sound like he’ll be crawling soon regardless?