My lightning USB slot on my iPhone has connectivity issues and won't charge is that covered under apple care

first ensure there is no debris in socket ,use an air brush or soft toothbrush to clean out

then if no improvement take to an Apple store Genius bar, as long as there is no user damage it should be covered by warranty

First of all, it is not at all clear whether your iPhone would need replacement. It may well not.

But if you have AppleCare (or AppleCare +), and your iPhone is still covered (which it is, as long as you are in the same country you were when you purchased it), take it to an Authoirzed Apple Service Center (or Apple Store) and they will determine the next course of action.