The first part looks correct, mate. It is not clear why you are attempting to import the key immediately after the ujust script enrolled it or why you’d use different syntax. I think need only to reboot after running the script.
No offense, but I think you probably just clicked the wrong option in the blue screen on reboot. It’s easy to do because the prompts are rather terse. Someone else asked for some screenshots of the enroll process in a different thread and I linked a video walking through the process:
MOK enrollment instructions my mum can understand - #2 by MaxJanky
I recommend you give that a look and emulate it when you reboot after importing any new MoK.