No, the Delkin Devices POWER CFexpress Type B 128GB is not compatible with the Nikon Z fc.
Nikon Z fc has an SD-only card slot (no CFexpress support of any type). Its own product page confirms only SD/SDHC/SDXC card compatibility -- CFexpress Type B uses a physically different connector and cannot be inserted into an SD slot.
What works instead
See all compatible memory card for the Delkin Devices POWER CFexpress Type B 128GB →“SD (Secure Digital) and UHS-I compliant SDHC and SDXC memory cards”
Last verified:
Compatibility inferred from spec rule (citations above are manufacturer-verified)