Once you login, go to "My Profile"

Then click on the "Edit Profile" button

Enter your backlink in the "Website" field under the 'Social Links' section

Go back to your profile page to check your backlink. Now click on the "Create a Viz" button

Double-click on the "Sheet 1" text as shown in the pic below

Write your content and create your contextual backlink as shown in the pic

Hit the "Publish" button at the top and give a name to your Viz

Go back to your profile where you'll see a Viz has been created under the 'Vizzes' section. Click on that Viz.

Voila! Both your backlinks are ready.