Are you using startup.txt for it?
if it doesn't say anything in chat you probably have the wrong file name for loading stuff automatically
- make sure it's not startup.txt.txt; if you have file extensions disabled try naming it "startup"
well, if the issue is that gel is loading but /allowmod isn't working, that's because /allowmod has to be in another text file from the /loadmod for the mod (a bit silly, I know, it's because of timing shenanigans) so you'll have to do /loadtext startup2 and put the allowmod in there or something.
...that said, if you aren't getting ANYTHING in chat, you have a different issue, since wherever and however you have your startup.txt it doesn't recognize it.