Why does Order Confirmation Approval request fail with error Transaction [ApprovalRequest] is not supported on this host?

SAP Ariba buying does not support Order Confirmation Approval integration.

When such approval requests are sent to SAP Ariba buying for an SCC supplier, the OC approval request fails with error in the SAP Business Network and the OC remains stuck in the queued status.

This failure can be handled through a customization in SAP Ariba buying. Please note that customization requests are no longer handled by Customer Support. All requests for customization should follow the procedure mentioned in the KBA:

What is the current process for customization requests?

The customization details related to this sceario:

1. From the Dashboard page, click Manage > Administration and make sure to activate the Advanced mode.
2. Click Customization Manager > Field Configuration.
3. In the Browse Classes box, search for and select the PurchaseOrder class.
4. Create a new computed field called cus_OCDeviationApproval

Details of the new fields:

1. Field should be a text field. Add a default expression to set the field to “notAllowed”.
2. The field should not be visible in the UI. Leave all related view boxes blank.
3. In the Advanced tab, choose the External Field option.

Press OK and in the Navigation Bar, click Customizing > Publish.

OC fails to consume in Ariba buying due to the allDetails tag

Purchasing > Purchase Orders > Order Confirmation
SAP Business Network for Procurement & Supply Chain > SAP Ariba Supply Chain Collaboration
SAP Business Network for Procurement & Supply Chain > SAP Ariba Supply Chain Collaboration > Supply Chain Collaboration - Fulfillment