That by itself doesn't mean it supports pd. If you scroll up in this thread to the pics I attached, you'll see the Anker one that says USB PD. Anything non Apple will most likely clearly state PD somewhere, especially if the watts etc are mentioned.
Also the cable needs to support PD. I think the older usb-c cables from Apple don't.
Also the cable needs to support PD. I think the older usb-c cables from Apple don't.
Last question. If a charger shows multiple out puts with various volts and amps, is it most likely working with pd?