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)
We use configurator to build an image. Configurator automagically unrolls the iPads in Casper. Then a policy takes over to install apps on the iPads.
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
Here is the official document on deploying iOS devices using configurator 2
