ipad not turning on

after I updated to ipadOS 14.7.1, my ipad pro 2018 11" is not showing any response.... when i connect to a charger, ipad logo appears for few seconds and goes off....and when connected to pc or mac, the endless blinking of apple logo appears (boot loop) and only dfu mode can be turned on.... no recovery mode no simple turn on.... when i disconnect from charger or cable ...i cant do anything and apple logo is also disappears....