Tax input not working

Hi, I can’t assign tags or categories to post thru MCP. Tags and categories are already created in WordPress. Post is created but no tags and categories are not assigned. Claude request:

{
  "post_title": "Facebook Lead Ads",
  "post_status": "draft",
  "post_category": [
    9
  ],
  "post_excerpt": "test",
  "tax_input": {
    "post_tag": [
      "facebook ads",
      "meta ads",
    ]
  },
  "meta_input": {
    "_yoast_wpseo_title": "Facebook Lead Ads ...",
    "_yoast_wpseo_metadesc": "Formularz Lead Ads ..."
  },
  "post_content": "<!-- wp:paragraph --><p>test</p><!-- /wp:paragraph -->"
}