To proceed to unlock your domain, open the "Domains and SSL" pop-up menu and click on "Domain Portfolio".
Next, find your domain and place your mouse cursor on the [...] menu.
If you have more than one domain, you can easily find them using the search engine in this section.
Click on the "Unlock Domain" option.
Finally, you must check the checkbox to agree to unlock the domain and proceed to the activation by clicking the green button.