Possibility to hook to custom PaaS solution for building the approval chain and write-back

Summary:

Possibility to hook to custom PaaS solution for building the approval chain and write-back to the Fusion transaction

Content (please ensure you mask any confidential information):

My client would like to build a custom PaaS solution for maintaining and building the approval chain for transactions occurring in Fusion.

For example, user creates a PR in Fusion RSSP and when they click on "Submit", we need a PaaS solution to build the chain of approvals and write-back to Oracle Fusion and update the BPM for that specific PR, then trigger the approvals within Oracle Fusion i.e. approvals should occur in Fusion application.