Hello everyone! 5 months and a week, still hasn't flipped over, even …

Hello everyone! 5 months and a week, still hasn't flipped over, even doesn't try. We do massages, holds his head well. Should I worry or is it still okay that at 5 months there are no attempts to flip over? Also, I would like to know how you spend your time during tummy time. 1.5 hours of tummy time, lying on a mat, excluding different procedures, but he doesn't like lying down for long, and on his arms at least 20 minutes rolls around. We play with toys, talk, but he gets bored quickly.