Question RTX 2060 connected, but not found in BIOS

[Nick altern]

I assembled my first pc yesterday. When I connected my pc to monitor via hdmi (I don't have vdi cable) and nothing happened on screen. Motherboard, connectors, pc case and even GPU lightened up, but there was no image. My friend suggested that it can be fault of either motherboard, CPU, PSU or GPU. So I disconnected GPU and tried again and it worked. But without GPU this pc is not completed. Full specs:

• CPU: i5-9600k
• Motherboard: Asus Prime z390-p
• Cpu cooling fan: SPC Spartan 3 pro he1024
• GPU: Asus GeForce RTX 2060 dual OC 6gb gddr6
• PSU: SPC supremo fm2 gold 750W
• ram: HyperX Fury 2x8gb 2666MHz
• case: SPC regnum RG4T
• HDD: Seagate Barracuda 1tb
• SSD: GoodRAM 256gb

Side note: I changed in BIOS option called "Primary display" from "CPU graphics (...)" to ”AUTO" and now it can be connected to GPU HDMI port, but it's still unrecognised in BIOS. No info about that, just LED on GPU is shinning and one of the is spinning for maybe 2 seconds and the second one is moving just a little bit while turning off the pc.

 

[the-GURU-man]

Check cables. Did you connect power cable to GPU correctly?

 

[Nick altern]

Yes, I checked it before. Everything is tightly connected.