You can search the DCS for requests by entering the British Library order ID in a search box on the DCS dashboard:
This means it is no longer necessary to first run your EHESS report in order to find the DCS request ID for your EHESS orders.
The BL order ID is included as a reference on your BL EHESS invoices.
After searching for your order number in this search box you will see the request which relates to it:
Click on this to open the request.