curl --request GET \
  --url https://omnicommerce.sg/api/v1/promotions/{promotionId} \
  --header 'Authorization: Bearer <token>'

const options = {method: 'GET', headers: {Authorization: 'Bearer <token>'}};

fetch('https://omnicommerce.sg/api/v1/promotions/{promotionId}', 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}"

headers = {"Authorization": "Bearer <token>"}

response = requests.get(url, headers=headers)

print(response.text)

{
  "promotion": {}
}