Can Apple replace your charger for free?

You may have to contact Apple or authorized official reseller to ask.

However there may be helpful information by confirming product status.

Included 'Apple accessories' are usually covered under original warranty.

• Check Your Service and Support Coverage - Apple Support

https://checkcoverage.apple.com/

If the charger was damaged, that probably won't be covered under warranty;

however there are instances where it could. ~ You'd have to talk to Apple.

General iPhone repair & service - outside accidental damage - are stated here:

• iPhone Repair - Official Apple Support

https://support.apple.com/iphone/repair/service

The Apple Limited Warranty

"Covers your iPhone & Apple-branded accessories against manufacturing

defects for one year from the date you bought your product. The Apple

Limited Warranty is in addition to rights provided by consumer law.

Our warranty doesn't cover damage caused by accidents or unauthorized

modifications. See the warranty for complete details. You can check your

coverage status online and update your proof-of-purchase information if

there's an error in our records. If our warranty, your AppleCare plan, or

consumer law don't cover your repair, you'll pay out-of-warranty fees."

Why would you expect them to do that?