The back is the most dominant position in BJJ and you DON’T want to lose it when you get here. Here’s how to reset the position if your opponent starts escaping so you can dominate and submit him from the back.

More resources on this topic include:

A Step by Step Guide To Hit Your First Rolling Backtake in Jiu-Jitsu, Even With ZERO Flexibility

and
Rolling Backtakes for Everyone
https://www.grapplearts.com/rollingbacktakes

Good luck with your training!
Stephan Kesting