1. Go to the "Layout"->"Sidebar Widgets" in your dashboard.
2. Drag&drop the links widget in the Sidebar section.

3. Click the setting icon to customize the widget.

4. Click the 'Add a Link" under the Links group. Enter the link name, URL and you can select a link image if you want to.

Make sure to click on the “Save” button to save your changes. 

Edit a Link: Click the edit or delete icon under the Action section

Add a Link Group: Click the "Add a Link Group" button to create one. You can edit or delete a link group by pausing your cursor on the link group name.