How do I authorize FreeDNS?
After you login to your Namecheap account, go to My Account - Manage Domains, then select Hosted Domains from the left navigation bar. If you don't see your domain listed on the screen, select Pending Domains. Click on the domain you wish to authorize. The following message will be displayed on your screen.
Simply click on the select authorization email link and choose an email address of your choice. Due to security reasons, authorization email cannot be sent to any other email address that the ones shown as your authorization email choice options.
NOTE: You must authorize within 48 hours of receiving the email. The domain will be allowed to use Namecheap's DNS only after a successful authorization.
For more information, please take a look at this video tutorial.