It is the only Mokoko seed you can find within this Island Lost Ark Gold. Finding the Mokoko Seed is among the easiest tasks you've completed in Lost Ark.
You just need to get there at just the Edge of the Island which is a bit larger that the rest of its corners, and you'll find the Mokoko Seed there. If you fail to arrive at the exact location on the initially, you will be able to check all sides of the Island within minutes due to its small dimensions.
Lost Ark - "Where It Belongs" Una's Task Walkthrough
Within Lost Ark, one of the regular and/or weekly tasks that you must complete when you reach the end of the game's level 50 will be the task of Una. You can pick any of the three of the three daily tasks in Una's task available from the Adventure tab located at the bottom right of your screen. Or, you can do it with the Alt+J key. But, one thing to keep in mind is to select ones that reward you with Leapstones for upgrading gears. One of the most highly recommended Una's Tasks to farm those Stones can be found in that of the "Where It's Belongs" quest. Here's a brief guide on how to complete the "Where It Belongs" Quest in Una's Task Lost Ark.
Lost Ark: How to Complete the Story
It is possible to get confused if you only read the in-game objectives. Read the quest description instead; it mentions something in the following manner:
"These Hoarfrost Robbers don't know when to give up. They continue to show up at the Frozen Harbor, taking from merchants and the residents."
This means that the first thing you must do is sail to your destination, the Frozen Sea Harbor in Shushire or teleport to it using a Bifrost best place to buy Lost Ark Gold. Don't forget to set the Bifrost's location to Shushire for the next time using the icon below the minimap, if you don't already.