Dear Ko_Baytar @Ko_Baytar,
Thanks for contacting us and letting us know your issue.
We regret to hear the PowerCore2010 Switch edition didn’t work and so sorry for all the inconvenience caused to you.
If you have a usb-a to usb-c cable (such as this one: https://www.amazon.com/gp/product/B01A6F3WHG ), please connect the usb-c port and output port at the same time to reset the indicators. After that, please use your Nintendo Switch wall charger (or Apple 61W or 87W USB-C wall charger) to recharge the battery again to see if the problem can be solved.
If the problem persists, you can contact us via support@anker.com and we will be more than happy to help you out as per the 18-month warranty policy.
Merry Christmas!