In what situations would an action be considered RMT?

I used to play on Artale, where the rules about player-to-player trading were extremely strict—so strict that even transferring potions to an alternate character could get your account banned. Because of that, I’ve become very cautious and only use the auction house for trading.

I’m asking this because I just gave my friend 1,800 Zombie Teeth to help them level up using exchange quests. They didn’t give me any items or mesos in return. I’m wondering—would this be considered RMT?

I only joined this server earlier this week, and I’m really interested in playing low-level PQs. But I’m hesitant to team up with other players on the server because I’m not a native English speaker, and full-English communication makes me a bit nervous. That’s why I invited a few friends to join me, and I’ve also given them some resources—like some unused Maple weapons and equipment.

I’d like to ask: at what point does something like this become RMT? If necessary, I can provide Discord chat screenshots to prove there’s no real money involved.