As the mainboard is 8bit (v2.2), there isn't a built in boot loader. The only two method to flash new firmware is via usb or is 8bit ISP flash tool. The screen firmware can flash via micro sd card.
DO NOTE: Creality Bl Touch kit wiring colour vary betwen batch. You would need to match the actual pin out from bl touch to mainboard not by the colours. If you don't you may short and damaged your board.
BL Touch Kit: https://store.dremc.com.au/products/bl-touch-auto-bed-leveling-sensor-for-cr-ender-series
Extension cable: https://store.dremc.com.au/products/2m-bl-touch-cable
Printed Bracket: https://www.thingiverse.com/thing:4324800
Please see the attached firmware for the screen and mainboard for
Install Video: (How to flash firmware): Note: Disregarding wiring, as it my vary between cable loom.
Please make sure wiring is correct before booting, we hold no responsibility for damaged mainboard due to incorrect wiring.