I have tested continuity on the switch and its wires. Connect the lead wires from the fixture to the black hot wire in the electrical box by twisting a wire connector to the ends of the lead and hot wires.

Need Help With Gfci Switch Combo Only Two Wir Leviton
Light switch has 2 black wires. If you have a ground wire connect the ground wire to the green screw. Bulb1 and bulb2 white and black wires connected to breaker white and black wires. Turn on power lights come on but switch has no control. Copper wire connected to junction. Its essential that you determine which black wire is hot before proceeding. The easiest and safest way is to use a multimeter to test for current.
You will have to get a 4 way switch for that position not a 3 way switch. Also the light fixture is. Red and black form the same cable will connect ot he brass screws then the red and black from the other cable will connect ot he black screws. However if you need to rewire a light switch or a plug socket you may occasionally come across two black wires. Connect the top screw to the wire that feeds to the light. If the switch that was there is a standard light switch with two brass screws on it and one green screw you can connect the red wire to either of the brass screws.
There is no problem with the switch. 4 way switches have 4 screws 2 will be black and 2 will be brass. I turn power on turn switch on no light. Repeat these connections with the two white. When you turn the power back on and if you want to swap the direction of the switch as in press down to turn off or turn on turn off the power and switch the two black wires. Connect the black wire to the other brass screw.
Make sure to shut off the power before doing this turn the breaker for the circuit off. Connect the bottom screw to the hot wire. Black means hot white signifies neutral and green indicates ground.