I want to use On Load Commands to immediately run the command /pregen start gen radius onloadpregen SQUARE 0 0 80 0 FAST_CHECK_GEN after creating the world. This is a command from the Chunk-Pregenerator mod. If you enter this command manually, it works. But if you add it to On Load Commands, then after creating the world it does not work. However, other commands (/gamerule) work. The debug.log file says:
[Server thread/INFO] [defaultworldgenerator-port]: DWG_INIT: You do not have permission to use this command