Yes, fully charge the Slim EX1 Wireless Keyboard before using it for the first time.

1. Connect the included USB-C cable to the USB-C charging port on the Slim EX1 Wireless Keyboard.
2. Connect the other end to a computer or a USB-C wall adapter. Any wall charger of 5W or more works.
3. Charge for 2 to 3 hours, or until the red charging LED turns green.

You can keep using the Slim EX1 Wireless Keyboard while it charges.