I believe all Ryzen processors or most of them anyways support ECC RAM Memory.
Your Threadripper supports ECC RAM MEMORY: https://www.cpu-world.com/CPUs/Zen/AMD-Ryzen%20Threadripper%20PRO%203995WX.html
You need to look at your Motherboard's QVL List for RAM Memory to see which ECC RAM Modules are compatible with both the Motherboard and Threadripper processor.
So you need to go to your Motherboard QVL List like this one I found as AN EXAMPLE ONLY since you didn't post the Make & Model of your Motherboard.
Gigabyte: https://www.gigabyte.com/Motherboard/WRX80-SU8-IPMI-rev-10/support#support-doc
NOTE: You need to open a Support Ticket not with AMD but with your Motherboard's Support which can advise you if your RAM is compatible or not if not listed on the QVL List which can be Out-Dated at times or with the RAM Manufacturer.