Babies tend to develop in 'stages' rather than ages. Once babies are out of the high Cot Death/SIDS risk period, approximately between 6-9months of age, have a strong neck and upper body strength control, are able to roll over and back again, then simply loosen the Safe T Sleep Sleepwrap baby swaddle a little more and using with your hands gently teach/help baby to roll within the Safe T Sleep Sleepwrap baby swaddle...they usually just 'get it' quite quickly.
At this stage of development then babies may sleep in their desired sleep positions. https://www.safetsleep.com/collections/sleepwrap-baby-swaddles
Pick a time when you are both relaxed and make it a little fun :) see FAQ#12 and #30.
All babies are different of course and this ‘learning to roll’ period may be a frustrating developmental period for everyone but whether in a Safe T Sleep Sleepwrap or not baby will be going through this stage. https://www.safetsleep.com/collections/sleepwrap-baby-swaddles
Without the Sleepwrap baby swaddle during this stage babies may end up in awkward, cold or potentially dangerous positions. They may also be at risk of standing, climbing and falling, this happens to nearly one in seven 0-2year olds who are hospitalized each year from falls. This being just the Tip Of the Iceberg!
Some tummy time and floor time on a nice, clean, smooth, warm mat/rug, out of drafty areas is a good time to encourage turning. Some roly-poly play, can be fun and expedite this new 'sport ' and developmental skill of rolling and turning.