I agree that it does look like the same board and therefore the software you found on another website should work. But maybe each manufacturer/seller has a different code? I would not normally think so.
I went back to the website where the relay device was and worked out how to download the software from their web site:
https://au.banggood.com/8CH-Channel-...N&rmmds=search
Then where it has the text:
>>>File download: Click here to open<<<
Right click on it and choose 'Save Link As" or similar depending on web browsers, and save the file to your hard disk. The file is in RAR format so you may need to download a free RAR extractor program from:
https://www.7-zip.org/
Keep extracting until you get to a folder called USBRelay. The files are there.
Ice in space limits the size of the files so I can't upload unfortunately.
The other thing too is this board is not 'serial USB', it's 'HID USB' which is much different and cannot be used with serial communications.
If you get stuck getting the files as they have not made it easy, I'll see if I can put then on 'BOX drive' or similar.
Cheers and Happy Happy.
Damien