To unlock the Moonlit Knight trophy in Shadow of the Tomb Raider, you will first need to complete the "Eternal Reward" side mission that is included with The Path Home DLC.
Once you have finished "Eternal reward" mission, go to the Mission Gate base camp and equip the
Silver Strike - Moonbeam bow and the
Midnight Sentinel - Farseer outfit. The Magic Touch skill will be obtained by completing the challenge tomb.
Once you have equipped the bow and the outfit, exit the camp and the trophy will unlock.