Each issued licence has a certificate page. The seal image for that record is served from this site. While the status is active, the mark reads as valid. When the Authority suspends, expires, or revokes the licence, the same address returns the matching mark.
Embed that address on a domain named on the licence. Do not copy the pixels onto another domain. Do not place the seal while the status is still “application received”.
The policy is set out in the Interactive Licence Seal Policy.