As shown in the example, the updated user application entitlements should be included in the data parameter.
Unlike Update User Apps endpoint, it is not mandatory to provide in the body request all app entitlements for a given app.
You can therefore update only one or several of them among the following body params: "install", "listed", or "products".
The "product" field is not required but cannot be set to "null". When provided, please specify all subfields specified such as in the example: "appId", "subscribed", "type", "sku", and "name".