Turn out all the lights on the top row, by pressing the lights on the second row that are directly underneath any lit on the top row. The top row will then have all it’s lights off.
Repeat this step for the second, third and fourth row. (i.e. chase the lights all the way down to the bottom row). This may solve the puzzle but is more likely that there will now be some lights left on in the bottom row. If so, there are only 7 possible arrangements. Depending on which arrangement you are left with, press certain lights in the top row and repeat the light chasing down the board. This works but is not the shortest answer which you can find using the ‘Solve’ button.
The table shows which top-row lights you need to press.
on top row
Press the ‘Mode’ button to change to create mode. You can then turn the lights on and off individually. You can check if your puzzle is solvable by pressing the ‘Solve’ button. If a solution is shown - you’re OK. To clear the board, press the ‘Clear’ button. To change back to play mode, press the ‘Mode’ button again.