Note: It is recommended that users have fully setup an AI's Factions, Animation Profile, and other basic steps before proceeding.
Coward AI will flee from detected targets they have an Enemy Relation Type with. If they are attacked by someone like a player who they have a Neutral Relation Type with, they will only flee from said target if attacked first.
To set an AI's behavior, go to the AI's Behavior Component and expand the Behavior Settings foldout. Set the Current Behavior Type to Coward. This will opening up additional settings specifically for the coward behavior type.