It surprises me because I can follow @[email protected]. However, it appears that in the configuration of that blog, the ActivityPub plugin is not activated. I think I am not using brid.gy.
The issue was wrongly formulated because the blog has not activated the ActivityPub plugin. Anyway, it surprises me that I can follow it from Mastodon, and that I can comment on entries from Mastodon. So, I guess WordPress has a built-in support for ActivityPub nowadays.
