Minecraft wiki entry for Item_modifier, associated text: set_lore—Adds or changes the item's lore.
 lore: List of lines to append or replace on the item's lore.
A line of item lore, following the Raw JSON text format. Components requiring resolution are resolved only if entity successfully targets an entity.
 entity: Specifies the entity to act as @s when referenced in the JSON text component. Set to this to use the entity that triggered the item modifier, killer for the entity that killed the this entity, or killer_player to target the killer only if they are a player.
 replace: Set to true to replace the existing item lore with only the lines in  lore. If false or absent, the lines are appended to the list of existing lines of lore.