Can't Use Disk After Flashing

This happened during my efforts of trying to fix my other computer. (See here for more). I was flashing a ISO image with balenaEtcher . Then I closed the lid of my laptop and left for 20 minutes. Strangely, after I come back, it was stuck, I couldn't cancel or anything. I quitted it and now I can't mount it anymore. When I try to restore it I got:

Restoring “disk3s2” from “Unnamed”

Validating target...
Validating source...
Repartitioning target device...
Could not change the partition type for /dev/disk3s2 - Operation not permitted
The operation couldn’t be completed. (OSStatus error 1.)

Operation failed…

When I try to erase it...

Erasing “disk3s2” and creating “UNTITLED”

Unmounting disk
Couldn’t modify partition map. : (-69874)

Operation failed…

And mounting it got me:

Could not mount “disk3s2”. (com.apple.DiskManagement.disenter error -119930868.)

What do I do?