This is also available as a file to download. To use the file, replace the size of the iframe and the URL of the assessment system with your own. And upload it to your SharePoint site and reference it from a CEWP.
Here is a screenshot of it in use, showing user ICS\john2261 being passed through to the assessment.
I was very proud to get this working! Many SharePoint users will use Windows Authentication or a custom webpart, but this route could provide an alternate route to provide simple pass through of participant name through to low stakes assessments, and I hope it’s helpful.