Replace your 2x4GB with 2x8GB.

You can’t add more sticks—you only have two slots. So yes, swap them out for 2x8GB to get 16GB total.

That’s a noticeable upgrade for most daily use, multitasking, or light gaming. No need to go higher unless you know you need 32GB. Two slots mean you’re limited to two sticks, so buy the capacity you want now and don’t plan on upgrading again until you replace the whole machine.