Canon EOS 80D Instruction Manual page 254

Wireless Flash PhotographyN
Setting the Flash Output Manually for Wireless Flash Shooting
When [Flash mode] is set to [Manual flash], flash exposure can be set
manually. The flash output settings that can be set ([1 flash output],
[Group A output], etc.) vary depending on the [Wireless func.] setting
(see below).
254
Wireless func.: 0
Firing group: 1All

The manual flash output setting is
applied to all the external Speedlites.
Firing group: 1 (A:B)

You can set the flash output
separately for slave groups A and B.
Wireless func.: 0+3
Firing group: 1All and 2

The flash output can be set
separately for the external
Speedlite(s) and built-in flash.
Firing group: 1 (A:B)2

You can set the flash output
separately for slave groups A and B.
You can also set the flash output for
the built-in flash.