Gebildet 12V Voltage Step-Up USB to 3-Pin and 4-Pin PC Fan Sleeved Power Adapter Cable+Splitter Cable 1 to 2 with Switch and Speed Regulator

My laptop's rear USB-C supports USB PD up to 100W When your laptop is a power sink it can consume up to 100W Has 20V/5A available per the manual. it does not, that's what it uses If your laptop has Thunderbolt/USB4 ports then it can supply 5V @ 3A = 15W. There is no laptop in existence which can operate as a USB C PD source with higher voltages and wattages. You could, of course, use a boost converter to get 12V out of it. Example, not endorsement: https://www.amazon.com/-/dp/B0DDSTQ743 12V voltage step-up circuit: Inside the USB housing is a voltage boost circuit that takes 5V and outputs up to 12V 0.4A for full power operation. A USB A female to USB C adapter will allow plugging this into a C port. Direct C to fan cables do not typically contain a step up circuit they just expect 12V to be supplied so that won't work. However, I found one that does: https://www.amazon.com/-/dp/B0DPZM7T3Q/ there might be more, cheaper, simpler. Good luck.