I bought this one on Amazon. Seems to be working good so far.

Maybe something like this? https://www.amazon.com/Headphone-Charger-Adapter-Charging-Compatible/dp/B09GYRH6YM

Just a cable, then plug it into a powerbank.

Or get a bluetooth amp/dac like the fiio btr5 (or btr3) so you can still use your wired headphones and charge.