A few things to look at.
If the psu does not have a native PCIe cable/s connected, it may not be capable of running the card. What is the PSU make/model/wattage ?
Was the monitor cable plugged into the rx570, did you change motherboard bios setting to run the card (pcie/peg ? setting (initial display first or similar wording)) ?
And one other possible setting in mobo bios would be uefi, not legacy boot for graphics.
Has any other graphics card been installed previously, or just been using the processor graphics ?
Ryzen 5 5600x, B550 aorus pro ac, Hyper 212 black, 2 x 16gb F4-3600c16dgtzn kit, NM790 2TB, Nitro+RX6900XT, RM850, Win.10 Pro., LC27G55T..