Context of "Unlock the ability to claim your own island and locate a map to Milky Bay" 4GKQ

You just completed two tasks at once. Search for "Milky Joel" in the Passive tier list, you will have to manually complete the task there as well. The passive tier is where tasks that aren't always available are placed, such as Castaways of the Arc (like Milky Joel), who can only be found certain days. You can only work on passive tasks that give experience when required by your active task, or if they give no experience at all. Check out rule §3.1 for details. To progress into the next tier, a number of passives must be completed. The number is found in the rules and indicated by the red blob in the tier list at the top of the page.