curl --request POST \
  --url https://omnicommerce.sg/api/v1/promotions/{promotionId}/products \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "productIds": [
    "f831911c-ba05-4c83-9a03-e026e0aaf102"
  ]
}
'

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({productIds: ['f831911c-ba05-4c83-9a03-e026e0aaf102']})
};

fetch('https://omnicommerce.sg/api/v1/promotions/{promotionId}/products', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://omnicommerce.sg/api/v1/promotions/{promotionId}/products"

payload = { "productIds": ["f831911c-ba05-4c83-9a03-e026e0aaf102"] }
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

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

print(response.text)

{}