The cheapest version that genuinely works, and it is much less than the videos suggest.
One light, in front of you, slightly to one side, above eye level, pointing at your face. That is the whole thing. Not beside the monitor pointing at the wall, at you.
What to use, in ascending cost:
A lamp you already own, moved. Free. Take the shade off or aim it at a wall or ceiling near you to soften it.
A sheet of white paper or card propped on the desk to bounce light back into the shadow side. Sounds absurd, works, costs nothing.
A cheap LED panel or ring light on a stand or clamp. Genuinely fine at the budget end for this purpose.
Slightly to one side matters - light straight on is flat and unflattering, and light from one side gives shape. Above eye level matters because light from below is the horror-film angle.
Then deal with the window. Either close the blind when it is behind you, or turn the desk so the window is in front of you or to the side. If you can face a window during the day, that is the best free light there is and you may not need a lamp at all.
Total cost for most people: nothing, or the price of a small panel.