Monitor more FPS than laptop screen?

Information: The monitor is connected to the laptop. The game in question is Fortnite. The laptop is called Tuf-Gaming FX505DT

First question: What should I play on to get the best possible graphics?

Second question: is it normal for the laptop to have less FPS?

1. Curved UHD monitor with 75hz and 4ms response time (290-360 FPS)

2nd screen of the gaming laptop with 144hz and 1ms response time (150-210 FPS)

I would always recommend capping the FPS to the HZ number of the monitor. (with V-sync or G-sync) This will give you the best gaming experience. 144hz is definitely better.

Since Fortnite has more of a cartoon childrens graphic, the highest graphic setting shouldn't be a problem.