What chemicals are used in receipt paper?
Have a look at wikipedia article on Thermal Paper. The whole trick is in the three components, which are mixed as solid substances and applied as coating to the paper. When you heat the paper, the solid substances melt and the coloring reaction occurs.

For this you need fine pulverized chemicals, stirred in a form of suspension in some volatile solvent and apply them on the canvas. It should not be a big problem, see e.g. patent on Thermal Paper.

If all this effort is for an artistic purpose, I would suggest as a first try to approach the companies manufacturing the thermal paper (there should be lot of them) and ask them for a bottle of the prepared suspension, telling them your plans. The success rate would not be high, but hopefully non-zero and it saves you 99% of work.

Additionally, the painting itself could be quite fun, I would expect the components to be UV-active, so the black light could help you.