Properly? The 9710 eats 130W or 90W, at 20V. Mind 130W is above the USB PD standard (max 100W), so you're not likely to find one, except Jackery and such. It may work with 45W or more power banks, but in a restricted mode.
Any USB-C laptop charger 65W or higher should work but, from what I have heard/read, non-Dell chargers will be capped at 65W regardless of their actual power delivery capability. If anyone can confirm or deny this, please chime in.