How do I run AtomIQ as an IBM i / RPG platform instead of z/OS?

Switch the workspace to AS/400 platform mode. That surfaces JT400 import, DB400, DSPF map preview, and the RPG analysis pipeline, and hides z/OS-only paths such as CICS, RSE, and DB2. Use this when the estate is IBM i, not when you only have a few RPG members on a z/OS workspace.