curl --request POST \
  --url https://api.embedreach.com/api/sending-domains \
  --header 'Content-Type: application/json' \
  --data '
{
  "apexDomain": "<string>",
  "subdomain": "<string>",
  "channelIntegrationId": "<string>"
}
'

{
  "success": true,
  "message": "<string>",
  "data": {
    "id": "<string>",
    "dnsRecords": [
      {
        "name": "<string>",
        "value": "<string>"
      }
    ]
  }
}