Onboard Mobo graphics Not Displaying

I've just finished putting together a new PC build:

• Mobo: MSI b550 gaming plus
• CPU: AMD Ryzen 7 3700

There's no GPU at this point but will be eventually, however, in the meantime I'd like to use my new PC.

When I boot it up, everything seems to be running, rgb is going, fans are all working but my monitor is faced with

no signal

After some research everyone seems to say you have to enable this via bios but... How can I if I can't display the bios? I've tried flashing bios via the button on mobo and still nada.

How do I get onboard graphics to work?

All Ryzen 7 CPUs require a discrete graphics card. You cannot use the ryzen 3700X without a graphics card as it has no integrated graphics. You will need to purchase a graphics card for using the processor.