curl --request GET \
  --url https://sandbox-openplatform.keysecure.io/open-api/v1/merchant/client/C202605220001/token \
  --header 'Content-Type: application/json' \
  --header 'Api-Key: your_api_key' \
  --header 'Timestamp: 1716307200000' \
  --header 'Access-Token: your_access_token'

{
  "code": 0,
  "msg": "Success",
  "data": {
    "client_access_token": "",
    "expires_in": 300
  }
}