Custom Mob spawn method - Cannot import spawn script

Hi everyone,

I'm messing around with MCreator in preparation for a camp I'm running in a few weeks, and I'm trying to make a custom mob (since I know that will be the most popular mod the kids will want to do!). I'm making a gold golem, complete with the same spawn method as an iron golem, just with gold blocks instead of iron blocks. I've gotten the procedure written and it looks right, but it doesn't want to let me add the script into the gold golem's file. The workspace is made in a NeoForge mod and I'm on Windows 11, if that helps. 

I've tried hitting the green plus button to make the script directly in the field, but there's no option to select the script to insert it into the spawn method. I've searched Youtube and the forums and haven't found anything that fixes the problem, so I'm kind of at a loss. I apologize if this is an already documented glitch!

I do have some screenshots that I took of what I have and what I can see, I can upload them if you need them!

Any and all help would be appreciated, thanks!