Nikon Z 6II Reference Manual page 696

4
f : Choose a channel for the remote flash units.
Set the remote flash units to the channel selected for
[Channel] in Step 3.
5
f : Group the remote flash units.
•
Choose a group (A, B, or C).
•
There is no limit on the number of remote flash units that
may be used. The practical maximum, however, is three per
group, as the light emitted by the remote flash units will
interfere with performance if more flash units are used.
6
C / f : Compose the shot and arrange the flash
units.
•
See the documentation provided with the flash units for
more information.
•
Test-fire the units and confirm that they are functioning
normally. To test-fire the units, press the test button on the
master flash or press the i button in the flash info display
and select [ c Test flash], and press J ( 0 659).
7
C / f : Take the photograph after confirming that
the flash-ready lights for all flash units are lit.
Optical AWL
654