For your reference, please check the following method:
Please go to [Mi Home/Xiaomi Home] APP >> tap [+] at the upper right corner >> select [Add device] >> select [Xiaomi Outdoor Camera CW300] or tap the magnifying glass icon at the upper right corner to search "Xiaomi Outdoor Camera CW300" >> select [Using Wi-Fi to connect] >> select [Wi-Fi] >> tap [Keep the network connection] >> tap [Add manually if there is no QR code] >> enter the 4-digit number broadcasted by the camera >> wait for the binding to be successful.