Need to load context segments through WebService

Summary

Need to supply DFF in CreateSimpleinvoice header flex context segment

Content

Need to load context sensitive dff on header while creating invoice

Hi, I am calling createSimpleInvoice Soap request , part of RecInvoiceService service.

I am able to create invoice without DFF and also with global DFF segment but finding it hard to send context based DFF.

  <inv:TransactionHeaderFLEX>
               <tran3:serviceDate>05/06/2019</tran3:serviceDate>
               <tran3:__FLEX_Context>WWT Sales Channel</tran3:__FLEX_Context>
               <tran3:__FLEX_Context_DisplayValue>WWT Sales Channel</tran3:__FLEX_Context_DisplayValue>
               <tran3:salesChannel>test</tran3:salesChannel>
            </inv:TransactionHeaderFLEX>

In this example Service date is global segment and gets loaded fine, also the context itself gets loaded but salesChannel which is a segment of context WWT Sales Channe does not get loaded, just gets ignored, I suppose I need to send something else but not sure what.