Operator realm members can't change difficulty setting.

I play on my friends realm with operator and I have no way to access game settings, I can use /gamerule, however I can not change the difficulty. Our main concern on the realm is that we change difficulty a lot on there because we have new comers and we have mob farms that need a higher difficulty. If we can not do that when the realm owner isn't on we could be stuck in hard mode as all the new comers join. I don't know if there's already a file for this but I did not see one. I would be nice if operators could access the game settings or if we could at least get a command for difficulty. Thanks