No unassigned hosts available with storage type FC. Commission hosts with physical NICs 0 &1 to Add Host from UI.
VMware Cloud Foundation 5.x
curl -X POST -H "Content-Type: application/json" -d '{"username": "<SSO_USERNAME>","password": "<SSO_PASSWORD>"}' https://<sddcmanagerIp>/v1/tokens | json_pp
Sample
curl -X POST -H "Content-Type: application/json" -d '{"username": "[email protected]","password": "****"}' https://198.51.100.1/v1/tokens | json_pp
curl 'https://<SDDC_MANAGER_FQDN>/v1/clusters/<CLUSTER_ID>/validations' -i -X POST -H 'Content-Type: application/json' -H 'Authorization: Bearer <BEARER_TOKEN from above command>' -d @clusterExpansionSpec.json