You need a HID driver that supports the Wii remote and can expose it as a normal gamepad.
On Windows, you can use jloehr's driver: https://www.julianloehr.de/educational-work/hid-wiimote/
On Linux, the kernel has hid-wiimote built-in. Simply pair your Wiimote with the OS BT stack (not Dolphin) and set up a udev rule to give permission to Dolphin to use the input devices. (DRIVERS=="wiimote", MODE="0666", NAME="input/wiimote")
On Windows, you can use jloehr's driver: https://www.julianloehr.de/educational-work/hid-wiimote/
On Linux, the kernel has hid-wiimote built-in. Simply pair your Wiimote with the OS BT stack (not Dolphin) and set up a udev rule to give permission to Dolphin to use the input devices. (DRIVERS=="wiimote", MODE="0666", NAME="input/wiimote")