availableQuests property
Indicates what quests are available for this Milestone. Usually this will be only a single Quest, but some quests have multiple available that you can choose from at any given time. All possible quests for a milestone can be found in the DestinyMilestoneDefinition, but they must be combined with this Live data to determine which one(s) are actually active right now. It is possible for Milestones to not have any quests.
Implementation
@JsonKey(name:'availableQuests')
List<DestinyMilestoneQuest>? availableQuests;