Unable to update billing frequency to One Time Billing using RESTAPI

Summary:

The following RESTAPI is used to verify the order billing frequency (item name in RESTAPI: PeriodicityCode).

・Update one billing plan

REST API for Oracle Fusion Cloud SCM - Update one billing plan

To update the billing frequency value from "Bill quarterly" or "Bill yearly" or "Bill monthly" or "Bill weekly" or "Bill daily" to "One Time Billing" What should I do?

I can update to "One Time Billing" from the screen, but

With RESTAPI, billing plans are not created for "One Time Billing", but billing plans are created for other billing frequency values.

There doesn't seem to be an operation to delete billing plans, so I don't know how to do it.