Dialog before SetupCompleteSuccess

Hi

I am trying to create a patch for already released major product. I have added a custom action in patch.

I would like to execute this custom action through action of the dialog which comes just before setupcompletesuccess dialog.

But I am not able to determine which dialog comes before Setucompletesuccess. Is there any way by which I can find button - action of this button is set with dialog "Setupcompletesuccess"

I checked all buttons in setupprogress dialog, but no button is set with dialog setupcompletesuccess.

Regards,

Amarjeet