Canon EOS 90D Advanced User's Manual page 215

ISO Speed Range When Set Manually
1
Select [z: zISO speed settings].
2
Select [ISO speed range].
3
Set the minimum limit.
Select the minimum limit box, then press

< 0 >.
Select the ISO speed, then press < 0 >.

4
Set the maximum limit.
Select the maximum limit box, then

press < 0 >.
Select the ISO speed, then press < 0 >.

5
Select [OK].
ISO Speed Settings for Still Photos
215