How to GET/CREATE structure from Sales by using rest API

Summary:

We are currently working with the REST API to retrieve and create structures from Sales. However, after attempting to use the ProductStructure/StructureHierarchy endpoint, we did not receive the expected response containing the required structure. Specifically, our goal is to retrieve the hierarchy in the following order: Model → Optional Class → Items via a REST API call. Any guidance on the correct endpoint or configuration adjustments to achieve this?

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