The rollover is a great move to control the ball in a tight area.
When you're under pressure, when there's many players around you and you need to control the ball, the rollover is a great way to do that because you don't use the inside of the foot or the outside of the foot, you rather use the bottom, the sole of your shoe to control the ball.
It gives you a big surface to control the ball, to move the ball softly, to beat a defender, or just to pull it back.
For example, pull it back over and use the bottom of the foot means that you have one foot on the ball, the other foot is planted nicely.
You need to bend your knees to keep the balance so you don't want to put too much pressure on the ball.
The body weight is entirely on the opposite foot.
And then you have a soft touch, ideally only with the front part of your foot, with the toe area, the first third of the shoe.
This would be the best way to do the rollover. With the heel maybe slightly up so that the foot is tilted touching only with the toe part. The heel is up. And you're most agile and you can do basically almost anything you want with the bottom of your foot.
Your rollover. It's a great way to gain more ball control, to practice at home, for example.
If you want to use it on the field, it's also a great way to get quickly from one side to the other, to shift body weight, to change direction, in front of a defender, or just to keep the ball moving and not be an easy target for the defender.
And those are some basics of doing the rollover.