Customer needs Icolor Sublimation transfer printers - Uninet Icolor 560 or more.
Please check below paper that works for decals and it’s the one used for candles. The adhesive is activated using water.
IColor AquaClear 1 Step Paper for Hard Surfaces and Candles 8.5 in x 11 in (216 x 279mm)- 100 pack
But recommend to request the artwork from customer to print a few samples.