wrote, that is a VERY underpowered computer for real-time video encoding. There are some users on this forum, that have spend a LOT of time, and are master of getting older, under-powered systems to work. So, it is possible, BUT expect to spend a massive amount of time becoming both an OS, and OBS expert, to replicate their results. There is NO easy/quick button/answer for this. OBS is a very powerful, flexible tool, which means what worked for someone else may not work for you (and vice versa).
In your case, you have a Celeron N4020 CPU @1.10GHz which is the absolute cheapest, lowest end new CPU you could get 2 years ago. To make matters worse, you only have 4GB RAM. And then you are running 3rd party security software (which I advise, but not in this case). And you are trying to do 4K video capture... is this even possible? I don't know.. maybe... but don't be surprised if it takes dozens or hundreds of hours or research to get something to work.. and even then, once working, you'll want to add something to make your recording look nicer, and that system won't be capable of it. so, recognize you will struggle with that system on recording, most likely regardless, with any real-time video encoding compositing tool.
if you REALLY want to record game play using OBS (or similar tool), ask yourself which you can spare? time or money?
There may be other options (and OBS forums wouldn't be the place to discuss such) which would work for you? For example, smartphones and tablet have built-in chips for video recording.. note ... no compositing, but maybe sufficient for you?