You must start by opening the mission's menu> access Story Quest in the lower left corner, keep in mind that you will need story keys, which you can access when you have eight daily commissions for each one.
And to unlock the events for Barbara, Noelle, Chongyun and Bennett, you will have to go to the Hangout Events tab.
These missions will reward you with valuable resources and since they are not time-locked, you can do it whenever you want.
You should know that their history keys have a limit of 3, so you will have to unlock the missions as you get the keys, so that they do not remain unused in the inventory.
After reading this guide on how to play Hangouts events in Genshin Impact, we hope you can unlock the keys and get the best out of the game.