curl --request POST \
  --url https://api.sendrealm.com/project-operations/campaign_audience_preview \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --header 'X-Sendrealm-Project-Id: <x-sendrealm-project-id>' \
  --data '
{
  "targeting": {
    "version": 1,
    "base": {
      "type": "all_contacts"
    },
    "excluded_audience_ids": [
      "3c90c3cc-0d44-4b50-8888-8dd25736052a"
    ],
    "contact_rules": {
      "kind": "group",
      "children": "<array>"
    },
    "push_rules": {
      "kind": "group",
      "children": "<array>"
    }
  },
  "app_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a"
}
'

const options = {
  method: 'POST',
  headers: {
    'X-Sendrealm-Project-Id': '<x-sendrealm-project-id>',
    Authorization: 'Bearer <token>',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    targeting: {
      version: 1,
      base: {type: 'all_contacts'},
      excluded_audience_ids: ['3c90c3cc-0d44-4b50-8888-8dd25736052a'],
      contact_rules: {kind: 'group', children: '<array>'},
      push_rules: {kind: 'group', children: '<array>'}
    },
    app_id: '3c90c3cc-0d44-4b50-8888-8dd25736052a'
  })
};

fetch('https://api.sendrealm.com/project-operations/campaign_audience_preview', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://api.sendrealm.com/project-operations/campaign_audience_preview"

payload = {
    "targeting": {
        "version": 1,
        "base": { "type": "all_contacts" },
        "excluded_audience_ids": ["3c90c3cc-0d44-4b50-8888-8dd25736052a"],
        "contact_rules": {
            "kind": "group",
            "children": "<array>"
        },
        "push_rules": {
            "kind": "group",
            "children": "<array>"
        }
    },
    "app_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a"
}
headers = {
    "X-Sendrealm-Project-Id": "<x-sendrealm-project-id>",
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

{
  "status": 123,
  "data": {
    "id": "<string>",
    "name": "<string>",
    "status": "<string>",
    "created_at": "<string>",
    "updated_at": "<string>",
    "targeting": {
      "version": 1,
      "base": {
        "type": "all_contacts"
      },
      "excluded_audience_ids": [
        "3c90c3cc-0d44-4b50-8888-8dd25736052a"
      ],
      "contact_rules": {
        "kind": "group",
        "operator": "and",
        "children": "<array>"
      },
      "push_rules": {
        "kind": "group",
        "operator": "and",
        "children": "<array>"
      }
    },
    "readiness": "<string>"
  }
}

{
  "status": 123,
  "error": {
    "code": "<string>",
    "message": "<string>",
    "details": "<string>",
    "issues": [
      {
        "code": "<string>",
        "path": "<string>",
        "message": "<string>"
      }
    ]
  }
}

{
  "status": 123,
  "error": {
    "code": "<string>",
    "message": "<string>",
    "details": "<string>",
    "issues": [
      {
        "code": "<string>",
        "path": "<string>",
        "message": "<string>"
      }
    ]
  }
}

{
  "status": 123,
  "error": {
    "code": "<string>",
    "message": "<string>",
    "details": "<string>",
    "issues": [
      {
        "code": "<string>",
        "path": "<string>",
        "message": "<string>"
      }
    ]
  }
}

{
  "status": 123,
  "error": {
    "code": "<string>",
    "message": "<string>",
    "details": "<string>",
    "issues": [
      {
        "code": "<string>",
        "path": "<string>",
        "message": "<string>"
      }
    ]
  }
}

{
  "status": 123,
  "error": {
    "code": "<string>",
    "message": "<string>",
    "details": "<string>",
    "issues": [
      {
        "code": "<string>",
        "path": "<string>",
        "message": "<string>"
      }
    ]
  }
}

{
  "status": 123,
  "error": {
    "code": "<string>",
    "message": "<string>",
    "details": "<string>",
    "issues": [
      {
        "code": "<string>",
        "path": "<string>",
        "message": "<string>"
      }
    ]
  }
}

{
  "status": 123,
  "error": {
    "code": "<string>",
    "message": "<string>",
    "details": "<string>",
    "issues": [
      {
        "code": "<string>",
        "path": "<string>",
        "message": "<string>"
      }
    ]
  }
}