That's a pretty low end computer nowadays and unreal engine 4 is notoriously difficult to optimize. Regardless, the game has *one* amateur dev (the creator) who does literally all the coding/engine work and the game is currently free, I wouldn't expect optimizations to start being parts of updates for potentially years, though I will say mrdrnose works far faster than most amateur devs so maybe sooner.
Also, you can add your native resolution to the assets files, but the game is only going to get worse to run and more glitchy as you play so unfortunately I would say it is better to simply not play and watch someone else play instead, or wait for either the game to be optimized or when/if you get a better pc. I'm genuinely surprised your pc even lets it run as one of the most common hardware issues in the forum is that the engine flat out doesn't support old hardware and won't let you start the game.