I know New Frontier Armory accepts them, but the vouchers can only be used on blue label guns. It’s best to call ahead and ask if they have what you want in stock prior to going.
N.F.A. had blue label G19 gen 3’s with night sights when I went, but no Gen 5’s. They had one commercial (non blue label) Gen 5 come in as I was filling out the paperwork so I opted for that instead.
I got to keep my voucher so now I have a reason to go back and use it