they all learn at there own pace and with my son he was the same way just give him a month or so he will get. I know he will.
His body shape may just not be conducive right now. He’ll figure it out and give you a great big smile when he does!
There really isn’t anything you can do to teach him to roll over, that is normally the last way that babies roll over. It will come before you know it. My boys started crawling before sitting up as crazy as that is.
What I did with my daughter was lay down with her just out of reach. I would encourage her, talk to her, laugh with her - try and get her to come my way.
If that doesn’t work, though, it’s quite possible he just isn’t interested in rolling that way. I have heard of plenty babies that went right to crawling before they even completely rolled over - it’s completely healthy, it just depends on what your baby’s personal goals are and what he’s interested in. Good luck!
my son had barely started rolling over and then about a week and a half later he was crawling. so my best advice just let him move at his own pace and don’t rush it. it goes by too fast as it is , just enjoy not having to chase him everywhere