An 8 generation old i3-4xxx?
your options are
1. Buy a newer, much more powerful computer
2. greatly reduce the OBS settings as that CPU is ancient for the VERY computationally demanding task of real-time video encoding.
You could get an nVidia GPU with NVENC to do encoding offload, but unless you can get such a card for really cheap, probably not worth investing in such an old computer.
I recommend monitoring hardware resource (CPU, GPU, RAM, Disk I/O, etc) utilization [for ex. using Task manager’s Performance tab and/or Resource Monitor] to see if your system is being maxed out with your settings [which is almost assured]
https://obsproject.com/wiki/General-Performance-and-Encoding-Issues and
https://obsproject.com/wiki/GPU-overload-issues
There are some who use OBS on CPUs like yours, but they are expert in optimizing both the Operating System and fine tweaking OBS. And their expectations coincide with CPU capabilities