We have a requirement to cancel the case such that the case status is going to be updated to "Resolved-Cancelled" when we click on a custom button.
We have an alternate stage "Cancel Case" in which we are updating the case status to "Resolved-Cancelled". We have created a custom button (with Lable as "CC") and a click event has been configured to call the "Harness" as below.
On Submit you can run a activity to raise a ticket to you alternate flow. ( Alternate flow should contain an assignment shape for your task preceeding a utility shape where u can call pxforcecaseclose api from the flow itself.