curl --request PATCH \
  --url https://api.tread-horizon.com/v1/sites/{site-id}/contacts/bulk_assign \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "contacts": [
    {
      "name": "<string>",
      "email": "<string>",
      "phone": "+18885551234",
      "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
      "_destroy": 123
    }
  ]
}
'

{}