Yes, the SanDisk Extreme PRO SD UHS-II V90 128GB is compatible with the Sony A7 IV.
Sony A7 IV's SD slot (Slot 2) requires Video Speed Class V90 or higher for its top XAVC S-I 4K (600Mbps) mode per Sony's own Help Guide -- SanDisk Extreme PRO SD UHS-II V90 128GB meets that class requirement.
“XAVC S-I 4K 600Mbps CFexpress Type A memory card (VPG200 or higher) SDXC V90 or higher”
Last verified:
Compatibility inferred from spec rule (citations above are manufacturer-verified)