Joying 11.6" Android Head Unit - Backup Camera Lines How to Enable & Adjust

The menu system for the new (as of Jan 2021) 11.6" Android Head unit Car Audio System has changed from their previous models.
This means that Joyings on-line help videos about the Reversing Bacup Camera don't help in this case. I'm sure they will be posting updated info soon but in the meantime here's how to turn the Bacup Camera lines on and adjust them.
I have to say that Joying's customer support have been very good both by keeping me well informed with the delivery and even more so with the after sales help.
I have exchanged several emails with a lady called Cindy who could not have been more helpful. There customer support has been excellent even with the time difference.
Hope this video helps - more including a full review and how to calibrate the parking lines to follow