I've got an ldr module with pot meter, but this shows either on or off.
All very well but how are you using it? What pins do you connect?
DO (Digital Output) from LDR to D34 on ESP32.
So if you use a digital output you will only get a digital output, either high or low. The threshold level will be determined by the setting of the pot on board.For an analogue output use the AO pin.
Something tells me that it has something to do with resistance,
I have tried to adjust the pot, but it does not helped me.
Someone is telling you exactly what is happening but you are choosing to ignore them.Have you tried using the AO connector and reading the analogue signal off that?How have you tried adjusting the pot? Expose it to a small amount of light, then adjust the pot until the signal flips from a big to small reading ( or the other way round ). Then that will be the threshold of light you need to trigger this DIGITAL signal.