This page of the Assassin's Creed Valhalla guide provides a detailed walkthrough of the Carrying the Torch quest.
Reward for completing the mission: 1700 XP.
Svend died, leaving Tove lost and in need of advice. Head to the nearby cemetery to talk to her.
The task is very simple - just chat with Tove or listen to her. After a longer cut-scene, the mission will be completed.