Nah man, I been stuck it seems on a quest? Alot of the new story quest updates like this one, never rly shows up for me.
Story mode only has 1 map.
Adventure mode has 4, the first map sometimes generates the path in a away (i do not remember if it's always) that you have to defeat a boss atop the mountain.
To do this, you first to into the town of Silajam (the first town), then you click the fountain in the middle of town and choose "listen to the crier" during day and you learn about the quest, then you need to click again on the fountain and choose "Take a walk around" during day, you should have an encounter with an adventurer that can tell you how to find the witch (also, if you succeed some certain checks, he gives you a gem that'll help you with the witch).
Then you find the witch in the witches hut encounter and you either give her the gem that you got from the adventurer or let her leech some of your total xp, then she'll makes you able to resist the snake god (or naga god or w/e) and then you'll just need to head for the mountain with the question mark found at the end of the map 1 and defeat the snake god or seduce her, then you can return to Silajam and click on the fountain and listening to the crier so you get a reward for the quest, you're also able to pass the mountain tile now in the map (or before getting the reward too) on to the second map.
I'm sorry this became a rambling wall of text, i'm sick (not corona, just a normal flu) and i'm delirious from the fever and the pain of coughing my throat into shreds.
TL;DR version of the quest:
go to silajam
click fountain during day
listen to crier
click fountain during day
take a walk
pass the checks with the adventurer
find the witches hut
pass the checks
find the mountain
kick some ass (or seduce with your ass)
go towards map 2
optional: get the reward