Below URL must be accessible from standalone agent depending on job type.
Software/Script job::- [protocol]://[fqdn/ip]:[port]/SoftwareRepository/[package-name]
Offline patch scan job: : [Protocol]://[FQDN/IP]:[Port]/PatchManagement/wsusscn2.cab
Patch deploy job: : [Protocol]://[FQDN/IP]:[Port]/PatchManagement/[update-id]/[patch-file-name]