Pannier rack for folding bike

What you need is a Carradice Camper Longflap or Odyssey XL onto the SQR seatpost quick release- with the large bands which fit round the oversized seat pillar. Works on an old style Birdy and the Halfords Intercity folder

Can you provide a link to the model?

In general, rear panniers on folding bikes can be tricky, because the short chainstays mean a risk of  interference with your heels while pedalling. And the rack needs to be high to keep big panniers out of the way, which inceases the size of the folding package (or even prevents folding altogether on some bike designs). Often it's easier to carry luggage at the front, or in a rack-top bag. I had a quick look at the Halfords website and a lot of their bikes have a mounting point for a front luggage block, which would take a quick release bag of some kind.

I have a non-folding 20 inch wheel bike and the best pannier solution I've  found is this front wheel rack from Tern, which holds two small panniers quite nicely