The pressure switch is located on the driver's side of the condenser, right by/next to/below the headlight. You can see it in the gap there. To remove/replace it, I think you are supposed to pull the bumper off.

Note the switch reads the high side before it goes into the condenser, and is required to have a reading (non-zero) to turn on the compressor. I'd start by replacing that switch. Note that if it's dirty/oily there, the o-ring is bad and it's been leaking. But I doubt it's leaking because it's holding 33 bars.

The pressure you are seeing at 33 bar is the low side, but in your case, it's the system pressure throughout, since the compressor is not turning on. I have experienced both a leaky switch (leaked past o-ring) and a bad compressor.