Supplier Site Assignment REST API which tables

Summary:

We have a requirement where we are using Supplier Create and Update events to drive our OIC integration. Normally, when a supplier is updated, the request gets stored in POZ_SUPP_REQUESTS and subsequently a change request number, requests status and object version number are updated which we are using to check when the supplier is updated.

But when we are using Supplier Site Assignment REST API - /fscmRestApi/resources/11.13.18.05/suppliers/{SupplierId}/child/sites/{SupplierSiteId}/child/assignments)

the supplier update event is getting triggered but the table POZ_SUPP_REQUESTS is not getting updated.

Is there any other table that we should refer in this case so that we can handle the supplier update event as per our requirement ?