Heroic Warfront: The Battle for Stromgarde

If you're coming at this like me and wondering, "why can't I do warfront quests on my alt when I have them unlocked on my main?", I finally figured it out.

The requirements are
"Come Sail Away" kul tiran arrival achievement
The [item=158075] in your possession (bank or wherever doesn't matter, you just have to do the quests with Magni)
Uniting Kul Tiras quest to unlock WQ

- If you can't see the portals and NPCs, you haven't finished Come Sail Away.
- If you can't pick up the Warfront Quests from Ralston Karn, you haven't unlocked the WQ
- If you can't pick up Uniting Kul Tiras on the boat to unlock the WQ, you haven't gotten your heart of azeroth yet.

We did Heroic Warfront today on the first day of Season 3 and quest didn't update, looks like it's bugged! It counted only for normal version of the quest :'(
Edit 1: Thread on forums here.
Edit 2: As of 1:15PM UTC 11 July people are still reporting not getting credit for quest even after GMs told them it was "hotfixed but you should try again to get quest reward" lol. Some people are getting it though so it's a hit or miss.
Edit 3: 4:20 UTC 11.07.2019 Rokhan came to us second time, we killed him before capturing all points, warfront ended, no quest progression.
Edit 4: Half an hour later I got credit for quest even though we captured only 3 points and killed Rokhan in our base when he came to us second time. Try abandoning quest and reaccepting again, maybe it helped me I have no idea. Super bugged.
Final edit: Blizzard mentioned it in hotfixes post from July 11 so it should be okay now (probably).

If you want to farm the warfronts with a Reroll for rewards/transmo, but you have never set foot in BFA with this character, This is what yoy have to do:

1. 
   
2. Start the Battle For Azeroth chapter by picking up Battle for Azeroth: Tides of War from [npc=49748] in Stormwind
3. 
   
   
4. If this is the first time you do this introductory quest, you will need to complete a scenario. Otherwise skip the scenario by talking to Jaina at Stormwind Harbor and go to the next step.
5. 
   
   
6. Once in Boralus, complete the quests from [npc=121235], up to A Nation Divided. Important not to be in a raid group, otherwise you will not be able to accomplish this. Last quest is phased out.
7. 
   
   
8. Once you have obtained the Achievement Come Sail Away, head to the inn and talk to [npc=154464] to collect A Dying World. Complete the quests in Silithus, until you obtain the [item=158075] and the Achievement Have a Heart.
9. 
   
   
10. Return to Boralus and speak to [npc=135612] on the deck of the ship "Redemption of the Wind" and complete the quest Uniting Kul Tiras.
11. 
    
    
12. From here, you can collect Heroic Warfront: The Battle for Stromgarde from [npc=142721] behind the ship, on the docks.
13. 
    

If none of your characters have done BFA, you may be required to do a series of quests before unlocking Uniting Kul Tiras. The first quest in this sequence is The War Campaign, which can be taken from Genn Greymane in the Harbor Master's Office.