This Unreal 5.3 Gameplay Ability System video is about creating a framework for the Third Person Character to apply default Gameplay Abilities and Effects. We do this by adding Arrays for Default Abilities and Default Effects, and then call InitializeAbilities and InitializeEffects from OnRep_PlayerState and PossessedBy. In these functions, we iterate over the Arrays to give the Ability System Component those Abilities and Effects. Lastly, we show how this is used in the Editor.
https://dev.epicgames.com/community/learning/tutorials/oMJP/unreal-engine-04-character-ability-framework-let-s-make-a-top-down-shooter