I made an NRF5340 board with NRF7002 myself. No external flash is used on the hardware.
Try running the light_bubl sample for ncs2.2.99.
I'm using this custom board with the prj_no_dfu.conf configuration with the following additions:
CONFIG_CHIP_SPI_NOR=n
After burning the program, it was found that it could not run anyway. Does matter necessarily require external flash support.