where to access quests for red dragon nest?

[Faraway]

March World Remaster patch says we are now able to experiene red, rune and ice dragon nest if we follow the main quests.

I am playing as Assassin and now my main quest stops at the temple knight outside GTS asking me if I already defeated Feder (proceed to Mistland if done defeating Feder in red dragon nest).
Seems like the main quest doesn't lead me to RDN. However, I do remember seeing one line during conversation with NPC that says the nest will be accessible throught some side quests.
The only side quests that appear are from Rubinart, who told me stories about Assassin (Assassin is created by Rubinart from fragment of beyond dragon) and IONA. Then the side quest ended at me receiving letter from Geraint inside GTS. I couldn't find any npc giving me side quests about red dragon nest. I have already unchecked 'Hide Quest Marker'. There is nothing in Remote Quest too.

Anyone knows anything?

[Medina]

if not the priestess of darkness in arendel try the one outside arendel gate in saints haven, next to the commission board

Battle ice dragon nest and rune dragon i believe both take place by talking to guard Phillips outside the merca dragon nest portal

Then FDN is by special sentry Louis outside Hirendel's barrier portal in Merca port

[Faraway]

okay, will try taht out. thanks