Add campaign contacts

Add one contact, or up to 500 at once. On a draft they are stored for launch. On a running campaign they are sent now. A contact already in the campaign is skipped, so a retry is safe. Each contact needs a phone_number; every other key is kept and can fill a template parameter through variable_mapping.

curl -X POST 'https://omnidim.io/api/v1/whatsapp/campaigns/{campaign_id}/contacts' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{}'

{
  "imported": 0,
  "skipped_invalid": 0,
  "skipped_duplicate": 0,
  "total_submitted": 0,
  "contacts": [
    {
      "index": 0,
      "contact_id": 0,
      "duplicate": false
    }
  ],
  "errors": [
    {
      "index": 0,
      "error": "string"
    }
  ]
}