Early on in Dying Light 2, you'll be tasked with going to one of the settlements and its people until Harkon is ready to contact you. It can be a bit tricky since the game doesn't tell you what exactly you need to do.
Dying Light 2 is finally out now and if you already downloaded and started playing, there's a big chance that you'll be stuck very early in the game due to one of the confusing story missions. It's the "Meet the People of the Bazaar" task that you need to complete before moving on further with the story.
The quest is not specific, basically, it says you need to meet the Bazaar residents but once you talk to everyone there, you'll notice that the quest will still be active. Here's how to complete it and trigger a call from Harkon.
How to complete "Meet the people of the Bazaar"
To complete this quest, you'll need to complete two other side quests - "The Spark of Invention" and "Cheers!". The Spark of Invention introduces you to a resident named Carlos who needs some material for his newest invention - the electric fence.
Make this quest active, follow the quest marker, find some parts and get back to Carlos where you'll get to see his invention in action.
As for the second quest, Cheers! requires you to unravel the mystery of poisoned water. Just like the first quest, just follow the quest markers and you'll be done fairly quickly with this one.
Once you complete these two quests, you'll trigger a call from Harkon, which will allow you to continue with the story.