I purchased the Raspberry Pi Asset UPnP and followed the directions to download and install the file on my RaspberryPi Model 3 B+. The download doesn't download the asset.tar.gz binary file. Instead it downloads a file called asset.tar.gz which is a text file and in the text it says that there was a 404 ERROR Not Found. It appears that the URL to download the file doesn't exist (I think).
Please see the attached screen shot (I've removed my order number).