Unable to Fetch Supplier Sites using REST API

Summary:

We have a requirement to check whether Supplier Site is created in Fusion or not.

But the Fusion user which is being used is not able to fetch the sites, even though the sites exist for the Supplier.

We tried using below REST API:

/fscmRestApi/resources/11.13.18.05/suppliers/{supplierId}/child/sites

We have given the standard roles to the user:

supplier manager

supplier administrator

Also we added below privileges using custom role mentioned in the below docs:

View Supplier (POZ_VIEW_SUPPLIER_PRIV)

View Supplier Address (POZ_VIEW_SUPPLIER_ADDRESS_PRIV)

View Supplier Contact (POZ_VIEW_SUPPLIER_CONTACT_PRIV)

View Supplier Site (POZ_VIEW_SUPPLIER_SITES_PRIV)