Thank you for reply! I couldn't solve the problem. I am using Raspberry 4 4gb by the way. I tried the configuration you provided also. Nothing has changed. I tried different modules. Again, nothing changed. I know that modules are working. I tested them with arduinos.
After some tests, I also found out that, relay actuator with button node sketch does not work without nrf24 connection. This is a big problem for me. This means, if my Raspberry is closed, I will not be able to control the lights with switches. There is a possibility that I can't modify the sketch to make the switches work without wireless connection (when I switch on, the lights will turn on, even if the wireless is not connected). My programming skills are pretty bad.
So, I tried to use an arduino with serial gateway sketch uploaded in to it. This way nodes connects to gateway and even if raspberry is closed, switch works!
I plugged the arduino to Raspberry with USB. And tried several configurations. None of them was successful. If you know the serial gateway configuration, can you tell me? I made several searches here but could not make it work. I tried /dev/ttyUSB0 and several other possible options. What would be the configuration script?