Eclipse based tools like z/OS Explorer and IBM Developer for z/OS, use a server on the z/OS system called RSED.
This is available on the ZD&T (ZPDT) system, but is hidden away.
You need to mount the file system
mount filesystem(‘FEK320.HALG320.ZFS’) mountpoint(‘/usr/lpp/IBM/zexpl/’)
Then start the server
It’s easy when you know how.