Game concept
Repair Artifact
The game also links it as Repair.
From the game's encyclopedia
When an Artifact has low Durability, you can choose to Repair it.
You need to pay Gold to Repair an Artifact.
Alternatively, you can choose to Reforge the Artifact.
The game's text for patch 1.20.1.2. Words in blue are entries of the encyclopedia: hover one to read it, as in the game.
Repair Artifact is an entry of Crusader Kings III's in-game encyclopedia. The game explains it: "When an Artifact has low Durability, you can choose to Repair it." The game also links it as Repair. Patch 1.20.1.2, from game/common/game_concepts/00_game_concepts.txt and game/localization/english/game_concepts_l_english.yml.
Source: game/common/game_concepts/00_game_concepts.txt, game/localization/english/game_concepts_l_english.yml and the English localisation, Crusader Kings III 1.20.1.2.