How to fast charge iphone se 2020

There is no “setting.”

You simply need a “larger / smarter” charger which self-negotiates with the phone so as to source charging power at a higher rate.

An Apple 18W charger is more than sufficient.

Correction … looks like they’re now 20W.

https://www.apple.com/shop/product/MHJA3AM/A/20w-usb-c-power-adapter

Plus you’ll need a “USB-C -to- Lightning” cable if you don’t have one already.