sGTM + Facebook CAPI user_data

I’ve watch and rewatched Facebook / Meta Conversion API setup + Event Deduplication [Step-by-step guide] video multiple times but can’t seem to figure out the user_data bit.

After I make a test purchase I don’t see this user_data in my sGTM container:

The only other place I’ve seen anything with user_data is here (Include user-provided data from your website), but its never mentioned how to create that variable and I don’t have it defined out of the box:
?v=ytNnSVodsA4&t=1012s&ab_channel=Stape (i can only post 1 link)

Thanks!

To see user data in your sGTM you need to send that user data from your web container to the server. Sending that is not different from any other parameter