Cant acces uefi firmware settings

Your graphics card will work whether you are in UEFI mode or Legacy mode. I would start looking at your graphics card power connections and your PSU. Make sure all of the connections are fully seated on both ends. Make sure you have the cable to the monitor connected to the back of the graphics card and not the motherboard. Make sure it is properly and fully seated as well. The bios initializes all hardware during post. Make sure the card itself is fully seated in the PCIe slot. Do the fans on the card spin up when you start up? Those are some of the places I would start looking.

essenbe said:

Your graphics card will work whether you are in UEFI mode or Legacy mode.

Well, not exactly. The issue the OP is apparently talking about is the de-facto standard BIOS setting that we all have seen many times before: when motherboard has integrated graphics and the user wants to install a discrete graphic card, the motherboard has to be told which graphics subsystem to activate first at boot time, before the OS loads.

Yes, this is done in BIOS. And yes, this option is typically available in legacy BIOS, no need to switch to UEFI. So, if the OP's machine supports legacy BIOS then it is just a matter of figuring out what key to press to enter BIOS setup and then finding the corresponding graphics option in BIOS.