This forum doesn’t appear to be listed on the new Discourse directory:
I’d suggest that it should be:
Opting in is straightforward. Head over to to Admin > Settings and filter for the term “discover”. Check the checkbox next to “include in discourse discover” and voilà, your instance will be included in Discourse Discover.
More info on this here:
Incidently neither are the Ubuntu, Nextcloud, Matomo or ONLYOFFICE Discourse forums but the GitLab and Icinga ones are.