I need to purchase chargers for my iPhone 12 Pro.

This is the recommended charger for an iPhone model 12 Pro:--> https://www.apple.com/shop/product/MHJA3AM/A/20w-usb-c-power-adapter?fnode=692163129c1e3a3ea590bc396dbf7021596eb380e41a8df0a0bb8dc1b51cc2e732686441d77d9b61dfa955a96d5d76e6b5bd5bbb80ec559711a6fdcc2cce1f98278bbdbc1d4d4f37fd37492e6a6f8537cfdabfbb28618303cc80ea7939d2e9c98849309a90a7d4cc73a6df0f1a4ff465

It is available from Apple Online Shop, or physical Apple Store, or Apple Authorized Resellers (among this list:--> Apple – Location Selector).

Regards

Giulio

Go to any Apple store or electronics store and get what you need.