On your first sign-in, you will be prompted to choose a username and a prefix, which will be unique to your account.

Once both fields are validated, you will be automatically transferred to your homepage, where you will be shown a table of the domains that you currently own along with information concerning their status details.

Deleting or adding a new domain is as simple as filling a form that will be shown once you click on the 'Delete' or 'Add Domain' buttons respectively.

Every new domain you set will have the following format:
<your-chosen-domain-name>.<your-chosen-prefix>.mydns.zone

The username that you have chosen when completing your registration is required for the Bearer Authentication, along with the token of the corresponding domain every time your router sends an update request to the MyDNS API. The token of each domain can be retrieved from the dialog that pops up when the 'View' button in the domains table is clicked.