My Xbee lost bootloader. How can i recovery it? URGENCY

When i change firmware of my Xbee XB24-Z7WIT end XB24-Z7PIT they lost bootloader and can’t access again.
What i need to for restore bootloader?
I have URGENCY. Thanks.

Dear William,

use xbee recovery mode and select the correct function set , latest version and recover it

it will work