curl --request POST \
  --url https:/api.autosend.com/v1/contacts/email \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "email": "[email protected]",
  "firstName": "John",
  "lastName": "Doe",
  "userId": "user_12345",
  "customFields": {
    "company": "Acme Corp",
    "role": "Developer",
    "plan": "premium"
  }
}'

{
  "success": true,
  "data": {
    "id": "507f1f77bcf86cd799439011",
    "email": "[email protected]",
    "firstName": "John",
    "lastName": "Doe",
    "userId": "user_12345",
    "customFields": {
      "company": "Acme Corp",
      "role": "Developer",
      "plan": "premium"
    },
    "updatedAt": "2024-01-15T10:30:00.000Z",
    "createdAt": "2024-01-15T10:30:00.000Z",
    "projectId": "229f1f77bcf86cd9273048038"
  }
}