Bring the graphics card or a new processor more FPS for fortnite?

And I play fortnite, you can't complain about the FPS but I like it more fluent and in endfights it can then even lagging.

My components:

GPU: Gtx 1050 Ti

CPU: Intel G4560

Now my question, what should I upgrade (especially only for fortnite) to get more FPS out?

In PC games, especially the graphics card brings more power so FPS. That's why you should, if you're only gambling, upgrade the graphics card. In addition, you can consider whether you use more memory.

Let's put it this way: In most situations, upgrading the CPU alone will not boost your FPS.
An upgrade z.b. On a GTX 1060 or RX 580, the FPS would increase significantly, but in combination with a CPU upgrade in resolutions below 1440p more than without.

You can just run the Windows 10 Task Manager in the background in Fortnite.

Then watch if the CPU or graphics card is running at 100% limit.

Mostly it is the graphics card, but the G4560 has only 2 cores / 4 threads, that's pretty little.

An RX 580 with 8GB is about twice as fast as the GTX 1050

Or take the new GTX 1660, which is https://gpu.userbenchmark.com/...3649vs4038 faster.

The 1660 definitely needs a stronger CPU.

Generally yes… Only Fortnite I do not know 100% if the G4560 brakes.