curl --request POST \
  --url https://api.pocketflows.com/rewards_programs/{id}/promotions \
  --header 'Authorization: Basic <encoded-value>' \
  --header 'Content-Type: application/json' \
  --data '{
  "name": "<string>",
  "start_time": "<string>",
  "end_time": "<string>",
  "points_multiplier": 123,
  "description": "<string>",
  "image": "<any>"
}'

{
  "id": "<string>",
  "name": "<string>",
  "start_time": "<string>",
  "end_time": "<string>",
  "points_multiplier": 123,
  "description": "<string>",
  "image_url": "<string>"
}