Programmatically turn off the monitor when youtube is running?

Question

Electronics

It's a shame for such a question, it seems to be banal, maybe I'm just stupid at 3 o'clock in the morning. Actually, when running a playback, for example, from youtube, it is not possible to turn off the monitor, it even forcibly goes out and immediately turns back on, respectively, the question is how to take away the power management rights of the monitor from the browser?