No, the Nikon Z9 is not compatible with the SanDisk Extreme PRO SD UHS-II V90 128GB.
Nikon Z9 accepts only CFexpress Type B and XQD cards in both slots — there is no SD slot and no Type A slot. SanDisk Extreme PRO SD UHS-II V90 is a full-size SD card, a physically different connector that cannot be inserted into either Z9 slot.
What works instead
See all compatible camera for the Nikon Z9 →“The camera can be used with CFexpress (Type B) and XQD”
Last verified:
Compatibility inferred from spec rule (citations above are manufacturer-verified)