are you attempting to enroll through DEP or manually?
if its DEP it should just work when you set them up.
as for manually, go to https://casper.youdomainhere.com/8443/enroll and follow the prompts (your port number may be different if you set it up on an alternate port)
i cant remember what IOS version it was that it changed but with current versions of IOS you need to use configurator 2 i believe.
so you need to setup your casper enrollment settings in its preferences. the enrollment URL should be the same as above except instead of "/enroll" you will use "/cloudenroll". Then you need to download your trust certificated from the JSS and it should all work when you run your Blueprint
EDIT - oops thought the post by CapU was a reply from the tread started... silly me, need to learn to read more lol