Does the canopy have any light sockets, or does it lack these as well?
If it does have sockets, you need to get the kind of tube that fits them - if there are T5 sockets you can't use T8 tubes for example.
However if there are no light sockets it is still possible to fit lights over the tank. My tank is custom built and came with brackets attached to the lid to hold fluorescent tubes and an external controller with sockets on the end of the wires that just fastened onto the ends of the tubes. I now have LED tubes fitted the same way - external controllers and the tubes just slot into the brackets on the tank lid.