Hi there and welcome
this is one of the worst things to do when updating the firmware as it can brick the printer meaning it has no installed firmware so no way to operate.
But we can see if it is recoverable.
Can you please remove the power to the printer (so unplug it from the power socket).
Then wait 10 minutes, connect the power again to the printer, turn it on and tell me please if it is now operating correctly.
Let me know the results please