You would have to order one. I doubt any retailer in north america sells them out directly.

https://www.aliexpress.us/item/3256802026159014.html

https://www.amazon.com/Original-M92T36-Charging-Replacement-Motherboard/dp/B07T7H99JX

https://repair.wiki/w/Nintendo_Switch_Error_Code:_2101-0001

If you have someone locally who could repair it I would at least get a quote from them first, it would be cheaper than letting Nintendo do it or buying a new system. And it would be the only method of keeping your save data.

Have you tried a lower powered charger? Like a USB-A cable? Sometimes the switch will refuse to charge from the official adapter because of issues like yours, but it might still work with lower powered devices as its simply charging and not trying to utilize its higher power inputs.