curl --request POST \
  --url https://api.shoppex.io/dev/v1/oauth/token \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/x-www-form-urlencoded' \
  --data grant_type=authorization_code \
  --data code=shoa_code_1 \
  --data redirect_uri=https://erp.example.com/callback \
  --data client_id=shoc_demo \
  --data client_secret=shcs_secret

{
  "access_token": "shpat_access_1",
  "token_type": "Bearer",
  "expires_in": 3600,
  "refresh_token": "shprt_refresh_1",
  "scope": "orders.read customers.read"
}