I did a quick search… any of these? Maybe one of them will lead to the one you’re looking for.
https://budgetlightforum.com/t/source-for-new-tir-throw-optics/63165
https://budgetlightforum.com/t/what-is-a-tir-lens/63268
https://budgetlightforum.com/t/essays-with-tir-lenses-on-convoy-s2-xml2-xpl-hi-update/47498