Hover over a box and click the edit button, bottom right.
Add a link and click the tick to save it
Click the + to add a box, give it a name and add your own links
mouse over to pause
Try it for yourself
Click "add a box" on the right, give it a name and save, then click the edit button in the box
to add a link. Enter a link name, enter the link and click the save button.