What does the manufacturer recommend? Do you have the operator's manual?

If not get the make, model and serial number and either call the manufacturer or search their website for lubrication information.

Ususally the chain drivin units dont need much lube, the belt dosen't need any lube or treatment. I would get the size of the belt and have one on hand, just in case it gets worn though. A genie screw drive would require a special grease.