Anything's possibe, but given the Jifo's configuration & folding regime it would be challenging. Dahon doesn't offer anything that I'm aware of.
May I suggest a rear rack on a short wheelbase bike with ISO305 wheels is not terribly useful (heel overlap). Dr. Hon was able to get a small, thin briefcase onto the rear rack of Dahon #1 back in 1982, and I suppose hypothetically provided a rack one might fit a small top case on a Jifo and still allow clearance for stowing the pedals. Suggest instead a Klickfix Caddy mounted on the handlepost below the bars.
A backpak on the rear-rack could keep the heels free. But maybe a rack is not compatible with the Jifo.
