You can find download link and CD Key for older versions of software like AutoTURN, in My Transoft Portal, under Home -> Download Products. Click on Download on the license and then select Download Older Versions
Then choose the version you would like to download and click on it.
Once you click on it, a new popup will show and the download link and CD Key for installation can be found. For example, AutoTURN 11 can be downloaded by clicking on that version.