There is one Pablo kiosk at this station (Channel Tunnel, 62903 Coquelles) that will allow you to scan your tax free form / barcode.
Batiment Dickens, Site Eurotunnel.
Junction 42b of the A16 motorway follow for "Terminal tourisme" NOT for "Terminal fret" when living the A16.
When arriving to the terminal, get you tax free forms, receipts and unused goods ready for inspection.
Pablo kiosk and customs offices are located in the Terminal.