How do I add tags to a PieFed post via the API?

I'm automating posts to PieFed and I can't get tags/labels to actually show up on the created post.

What I'm doing

I'm POSTing to create a post with a body that includes hash-style tags, something like:

Some post body here

#tag1 #tag2 #tag3

Or sometimes I try passing a separate tags field in the JSON body.

Current code / request

// Replace this block with your exact current request

POST /api/v3/post
{
  "community_id": 123,
  "name": "Example post",
  "body": "Body text\n\n#testing #automation",
  "url": null,
  "auth": "<jwt>"
}

What happens

The post is created, but the tags never appear as clickable tags on the post. I don't see them in the API response either. The paragraphs/body text works fine.

What I've tried

• Adding #tag tokens in the body text
• Sending a top-level "tags": [...] field
• Using both the Lemmy-compatible API and PieFed's /api/alpha/post endpoint

Specific question

What is the current supported way to add tags to a PieFed post via API?

• Should tags be embedded in body as #tag text?
• Is there an actual tags field/list in the post create payload?
• If tags are supported, what exact keys/values are accepted?