For Change Management Systems, the approval is created based on the ticket(s) associated to the deployment request. This association is either through a reference on the deployment request (either through the FlexDeploy application UI, or via the REST API), or due to auto-creation configured at the folder level. When the ticket is approved in the external system, the FlexDeploy approval task is automatically approved.
Pipeline Approvals
Similar configuration can defined for External Approval Gates within a pipeline. When using pipelines, the CMS configuration defined on folders or projects are ignored, since the configuration is used from the External Approval Gates themselves. See Creating/Editing a Pipeline Version for details regarding the External Approval Gate.