That's it, if you want to leave a VR practice and redo it again later, you can.
The only thing you have to do is select the option "Leave". A message will pop up: "¿Do you want to leave? If you leave the VR practice will not be sent" and you select the option "Yes".
That way, you will not send us send us the previous VR practice and you will be able to leave, in order to do it again in the future o to repeat it.