Stair Switch Installation for Simultaneous Two-Lamp Control - 3-Wire Cable Setup Advice

Welcome
I have a huge problem. I bought a stair switch (with two buttons) - because I liked it. The seller said that it can also be installed as a regular one. I have a pulled 3-wire cable and when I installed a switch, one button turns on one lamp, and the other turns on the second lamp, but it also turns off the first one! - and I would like to have both enlightened at the same time .
Can it be connected somehow without pulling a new cable / buying a new switch?

Regards
Sylwia Hausner

Upload a diagram / photo as you connected it.

If it's a double staircase switch, you need to think about it a little more
You need to separate the power supply into two contacts, and the wires from the lamps to the appropriate contacts :)

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