How to create an expression using REST API

Summary:

In the document https://docs.oracle.com/en/cloud/saas/sales/faaps/op-incentivecompensationexpressions-post.html,

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in the above document the example payload is:

{ "Name": "Credit Amount Expression", "OrgId" : 204, "Description" : "Expression for a basic credit amount."}

It only creates expression with name but not the expression itself, say I want to create an expression SUM(Credit.CreditAmount)

How do I do that? please help I dont find any examples.

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