curl --request POST \
  --url http://localhost:8080/cabinet/admin/partners/{user_id}/campaigns/{campaign_id}/unassign

{
  "detail": [
    {
      "loc": [
        "<string>"
      ],
      "msg": "<string>",
      "type": "<string>",
      "input": "<unknown>",
      "ctx": {}
    }
  ]
}