I don't suppose its an iPhone 8 or above with wireless charging? If so you might just get him a wireless charging pad and use that. Here's my recommendation......
https://forums.imore.com/community-r...t-charger.html
iPhone parts are VERY hard to get, as Apple does not want people making home repairs OR using non certified 3rd party repair shops. That being said if you look around you can probably find the part, check Amazon and eBay. Here's some helpful info on the repair....
https://www.imore.com/how-fix-broken...-port-iphone-5 (iMore - iPhone 5)
https://www.ifixit.com/Guide/iPhone+...lacement/29915 (iFixit - iPhone 6)
https://www.ifixit.com/Guide/iPhone+...lacement/78122 (iFixit - iPhone 7)
It does appear fairly complicated, so you MIGHT want to get Apple OR a 3rd Party to do it for you, OR as I said IF its an 8 or above and it has wireless charging, then just get a 20-100 dollar charging pad.
Is it time for an upgrade? Perhaps you can start a new finance with your carrier and not have it hurt too bad?