I recently bought a month of IPTV service from IKS66. In the confirmation email, I was sent a link to 66.iptv66.tv. But when I click on it I get "Your STB is Blocked. Please call your provider." error.

The "Mac Address" is set to 00:1A:78:XX:XX:XX with last six digits pointing to the mac address of my device.

Please close this thread, I have found my solution. I changed mac address to a custom address and used that in IPTV Stalker in Kodi.