VVF (VMware vSphere Foundation) licenses are used in the environment.
Due to this Fleet Management capabilities are not available in VCF Operations. (Only available with VCF licenses)
How should VCF Operations be updated without Fleet management?
VCF Operations 9.x
Fleet management capabilities are available only with VCF license as per :
VMware Cloud Foundation and VMware vSphere Foundation:Feature Comparison & Upgrade Paths