Access 'ContainerToInvert' file

Hi Everyone,

I had my macbook air fail to restart and have tried several things to save the hard drive so I can wipe it and keep the files needed. I encountered the same "fail to invert" problem with APFS Volumes many seem to encounter and cannot get fuse & xmount to work on my older iMac to try the terminal commands listed on other sites and have tried the .dmg trick to no avail.

Any advice would be appreciated as I have a lot of important data on this hard drive I need for work.

Thank you