Can its gpu be upgraded? asus vivobook m15qa

It is highly unlikely.

If the graphics are separate from the CPU then they will 98% likely be direct-soldered to the motherboard. If the graphics are being sourced from CPU-integrated graphics then it depends if you can upgrade the CPU - but it is likely the CPU is also soldered to the motherboard.

You CAN check though: go into your device manager and get the exact CPU model your laptop has, then either google it or post it here so we can look it up to find out if it is a BGA (Ball Grid Array - meaning soldered on) model or not.

If the GPU is being sourced from integrated-CPU functions, and if the CPU is not a soldered on model (it is far more likely these days it will be soldered on though), then you could upgrade your graphics to an extent by upgrading your CPU. But even if you can upgrade your CPU, you would want to be careful to compare the power consumption / thermal power profile (TDP) of the CPU you already have with the one you are thinking of replacing it with - laptops are typically designed with tight tolerances on such things, as a cost saving measure if nothing else. You wouldn't generally want to pop a CPU with, say, 230W TDP in to replace one that had 105W TDP. The result would probably be that you kill the laptop, or more hopefully that it would simply refuse to boot.