You may have Vsync enabled, which is why you think your FPS is not improving. Your laptop has a 144hz monitor, meaning it can't display more than 144 FPS.
With Vsync enabled, your laptop will not render more frames than your monitor can display, because there is no point in doing so.
There's not much you can do with improving laptop performance, your best bet is to ensure that your drivers are updated, and to keep your components cool.
I would monitor your component temperature, an easy utility is MSI afterburner, though your laptop likely came with pre-installed software to do the same job.
Laptop cooling pads can really help, but don't bother unless your temperatures are too high.