We currently don't highlight that there are publically available API docs available from the main documentation site: https://koha-community.org/manual/latest/en/html/webservices.html#versioned-restful-api-effort
Thanks for pointing this out, Martin! Looks like a nice bug for a Documentation beginner.
Merge request open at https://gitlab.com/koha-community/koha-manual/-/merge_requests/996/diffs