How to recover a disk after Ext2Fsd (file system not detected)?

Question

linux

I wanted to connect a disk with Debian 9 to Windows 10. I have a 750GB hard disk, divided into 3 partitions, 2 of them in NTFS, one was Debian 9 (ext4 file system).
I used the Ext2Fsd-0.69 program, followed the instructions, mounted the disk, opened the explorer - the disk was not formatted (did not format it). I unmounted, rebooted the computer, tried again, again the same thing, poked around in the connection parameters, now I don’t remember exactly, but it seems like I chose a different type of file system (extended), mounted it. Now to see a disk in general ceased. I spat on this idea, deleted the program, rebooted, but the computer cannot find GRUB (I have it installed just on the debian partition). Now it doesn't boot on either Win10 or Debian. Later Windows restored. But the debian section does not work.
What I tried:
scan with the program testdisk-7.1-WIP.win
I select a disk, I select partition table type - "Sun"
Then "Analyze", it does not see anything, I select "Quick Search", it finds it.
I choose "write". And he writes to me "Function write_part_sun not implemented"
I did not format the section and did nothing more.
Tell me what to do, I really need to restore one working folder with debian. Restoring files will be too hard - there are node.js files, there will be a lot of them

Answer 1

Restored all files! I used R-Studio, the program found my partition in the unallocated area, then I clicked to open the found disk in Explorer and restored all the files while maintaining the hierarchy.

Answer 2

If you need the files, then go to the recovery office.
If you want to do it yourself, then walk the hex around the disk with your hands in the whole node, it’s not difficult to find, it just takes many days

Answer 3

Don't use Ext2Fsd 0.68 or earlier versions with latest Ubuntu or
Debian systems. Ext2Fsd 0.68 cannot process EXT4 with 64-BIT mode
enabled, then it could corrupt your data. Very sorry for this
disaster issue, I'm working on an improvement.
The driver cannot yet work with EXT4 from the latest Ubuntu Debian. The developer warns that the data may be corrupted.