In AppleCommander 1.9.0 on macOS 12:

• In the main window, click "Create…"
• Click "Next >"
• Type a name and click "Next >"
• Click "Nibble ordered" and click "Finish"

In the title bar of the resulting window, the disk name ends with ".po" as it does for a ProDOS-ordered image. Looking in the "Reorder…" menu, "ProDOS Order" is checked. I expected the disk name to end with ".nib" and for "Nibble Order" to be checked in the menu.