It’s very hard to get an LF reading on my NExT while using the Icopy-XS. It’s much easier on my Proxmark RDV4, but still has to be positioned just right.
One thing you can try is to plug the Icopy into your computer and run the Proxmark binary on the computer. You could then run commands such as ‘lf tune --mix’ to find a good position and use the Icopy as a normal Proxmark. You should have access to all Proxmark commands.
If you’re on a Linux machine, you can run the compiled binary @ icopyx-teardown/proxmark3/client_linux_unofficial/proxmark3-804fef2ab at master · iCopy-X-Community/icopyx-teardown · GitHub and have full access to the Icopy.