Canon EOS R5 Mark II Advanced User's Manual page 176

Setting ISO speed from a screen of options
1.
Access the screen of ISO speed options.
2.
Select an option.
Note
To specify [AUTO] when setting [ISO speed] in [
press the <
Tap the ISO speed in the lower right of the screen.
Turn the < > dial or select a registered setting value.
You can register frequently used ISO speed setting values by
specifying an option other than [AUTO] and selecting [Register].
> button.
: ISO speed settings],
176