Enable Cloudflare for Three Test Websites

I signed up for a cloudflare partner program and got the approval. Integration with WHMCS has been done, but on adding any new domain from WHMCS I got the following error “Invalid Headers” with error code 6003.
May be this because my email address not verified , I’m not received the email verification and don’t know how to resend it.
May be this is because I’m not added the 3 test domains to my partner account. If this right could you guide me how to add them.