post https://apps.hivestack.com/api/v2/creativemediaownerapprovals//convert
When a creative is sent for approval, a creative approval object is created with mode generic (G). Before being able to use network specific approval, this endpoint must be called in order to change the mode. When switching from generic (G) to network specific (NS), the original creative approval object will be deleted and multiple new objects will be created, one for each network. This allows the media owner to then select which networks to specifically approve the creative for.