Tag required
tag.required · HTTP 400
What it means
DELETE /v1/inboxes and DELETE /v1/authenticators purge everything carrying a tag, and the request named no tag or one that is not a valid tag.
What to do
Call DELETE /v1/inboxes?tag=<tag> or DELETE /v1/authenticators?tag=<tag> with the tag your test run gave them. To delete a single one, use DELETE /v1/inboxes/{id} or DELETE /v1/authenticators/{id}.
Every error the API returns is a JSON problem (RFC 9457) whose code names it and whose type links to its page here. See the docs for how the API works.