Electrician here...
Like the previous person posted, throw those push terminal plugs out and go for screw terminals! You probably have other outlets on the same circuit , if they are feeding your outlet with push terminals, they too could melt and need to be replaced!
If you can, also replace with a 20a commercial grade outlet (stronger & better plug contacts), instead of the 15A cheapo's. Technically this violates code if you have 14awg wiring supplying it and a 15a breaker (but if 12awg wiring and a 20a breaker, then you are good), so put a label on the outlet cover saying (for 15A use only), and make sure your charger is below 12a.
US wall plug/outlets just aren't designed well enough for sustained high currents. So, I also upgraded my US EV charging outlet to twist lock plugs/sockets, and cut my cord plugs off the chargers and reattached twist locks to them, and use lots of no-ox dielectric grease. Seems silly, but I also made a small outlet plug to twist lock adapter for traveling just in case. This resolved all daily overheating issues.
Lastly, not all EV wall chargers are created equally, look for < 8 - 10amp, or adjustable current chargers. I bought a charger rated at 12a 110v / 16amp - 220v, and that thing roasted so many US plugs/sockets/cords, hence the twist-lock upgrades.
If you need more power and faster charging, upgrade the outlet to 220v, since most level 1 chargers can handle both 110/220v. Might be easier and less costly than you expected, especially if it is the only outlet on the breaker, so then a super easy switch to 220v!
Europe plugs are rated for 16A at 230v, but they still get hot too... The wiring terminals are a bit different (inferior in my opinion) here, so I always use no-ox dielectric grease or solder the wiring to the terminals for best thermal/electrical contact. No melted/blown EU sockets/plugs since the solder mods.
As a techie, this all seems elementary to me, but I get it may be confusing, so just ask if you need help.
Best of luck!