Advice on voucher that Dollar operates through/in conjuntion with Hertz in Lisbon airport.

The fact that Dollar is represented by Hertz, was not clear. On the Dollar counter there was a sign with a finger pointing to the left, however unclear that left meant the Hertz counter next door as opposed to a self service kiosk placed on the Dollar counter where you are supposed to introduce your RA no. or Vehicle registration no. and then proceed to the car park.