Update Order
Updates B2B information on a specific order based on the `bcOrderId` provided.
The `bcOrderId` parameter must include a valid BigCommerce Order ID (**not** the B2B Edition order ID returned in certain Orders endpoints) for the request to be successful. You must also include at least one of the following fields in the request body:
- `poNumber`
- `extraFields` (array with `fieldName` and `fieldValue`)
- This array must be included if your store has required order extra fields.