Here’s a concise feature description you could use for a developer, a product backlog, or a platform request: Support Upload of Season 2 M4B Files
Medium / High (if S01 upload already supported)
Enable users to upload Season 2 content in M4B format (Audiobook M4B, chapterized).
It sounds like you're requesting a feature related to uploading (S02) of a specific audio book or podcast in M4B format (which is an audiobook format, often chapterized).