The number one backlit wireless keyboard our clients purchase, by far, is the MX Keys

Logitech MX Keys Advanced Wireless Illuminated Keyboard, Tactile Responsive Typing, Backlighting, Bluetooth, USB-C

Followed by the more budget-minded K637

Earto K637 Light up Wireless Keyboard and Mouse, 2.4G Windows/Mac Backlit Wireless Keyboard, Type-C Rechargeable