Purpose : Ideally workflow task reside in SAP business workplace inbox( SBWP).Sometimes we need the workflow task to be visible in Fiori Inbox.
Solution:
Below config is needed to send custom workflow task to FIori Inbox
1.Maintain Task Names and Decision Options -- WF and Task
View Cluster: /IWWRK/VC_WF_STEP
IMG Path: Sap NetWeaver-> SAP Gateway Service Enablement->Content-> Workflow Setting->Maintain Task and Decision Option

Maintain Workflow ID and Step Number

Then we can maintain decision key which we can maintain outcome example Approve or Reject

- Scenario Definition
View Cluster
😕 IWPGW/VC_TGW_SC
IMG Path: Sap NetWeaver-> SAP Gateway Service Enablement->Task Gateway->Task Gateway Service->Scenario Definition

Create new scenario and enter Service as /IWPGW/TASKPROCESSING

Fiori Inbox

Conclusion : Existing Workflow task can be send to Fiori inbox via Above mention Config without any development in Front end.