External power source

I'm looking to power my Lattepanda delta 432 from a 12V tractor battery. I have a buck converter which can be found here (https://www.amazon.ca/Yeeco-Converter-1 ... merReviews). I found a source that seemed to suggest you could power the panda from GPIO pins. Is this possible? I couldn't confirm this with official sources. The other option I am considering is to to use this USB-c step down converter found here (https://www.amazon.ca/HOMREE-Step-Down- ... ics&sr=1-2). I know the usb-c connector on the Panda is safer because of onboard regulators/fuses. My only concern is that this converter is only rated for 15W(5V 3A). Will that be sufficient? I am afraid of underpowering the device. I'm not sure how I would connect the battery via the 12V 4PIN power connector? Hopefully, my post is clear. Are there better options I have not considered? Any advice is appreciated.