Why por_requisition flexfield not available as Source in SLA and how to enable it.

Summary:

We need to define a SLA rule that derivate the value from an attribute of por_requisition_flexfield but it doesnt appears as a source, just po descriptive flexfield, even XCC flexfield appears. Why requisition flexfield are not available and how to add it ?

Content (required):

We need as a valid source por_requisition_flexfield header or line, but we need it to build the requisition charge account.

Version (include the version you are using, if applicable):

23C (11.13.23.07.0)

Code Snippet (add any code snippets that support your topic, if applicable):