Well the current ongoing event is probably the easiest event out of all the events the game has had (excluding the web-based ones). The current event just needs the player to find 2 60 Iron Coins per day and that's it.
Literally, one just needs to teleport to the Treasure Area shown in the Treasure map and just casually walk inside the circle. Whenever near the treasure (iron coins) a golden light will show and all you have to do is just click the prompt-up "dig". And No time limit! Lol Again, the easiest event ever. XD
At the moment I'm now on Treasure 9 which would unlock in the next 9 hours.
As for the rewards it's actually pretty good with 3 100 PRIMOGEMS as the most notable one. I have already redeemed it in preparation for tomorrow's new event. I'm planning to pull for GANYU. XD