It sounds like you may have seen the physical drive appear in Disk Utility.
FYI, macOS is not very good at being able to access or troubleshoot issues with a foreign drive.....it doesn't even do very well with the Apple internal drives from the factory, much less a third party file system that may be corrupt, or especially a drive that may be having hardware issues.
Unfortunately there are a lot of ways to copy a drive....many of which may not allow a Mac to access them.
You also have to consider the possibility that the SSD is bad & is why the Windows computer "died".
While I applaud you for wanting to do this on your own, you may need to contact a local tech to assist you in assessing the SSD & recovering the files from it. Sometimes being able to physically see things first hand is required to properly assess a situation.