How to create a PO priced on Secondary UOM?

Summary:

We have a requirement to price the PO on Secondary UOM. Documentation says it can be priced at secondary UOM.

Details -

Created an item with Primary UOM = 'Each' & Secondary UOM = 'KG'

Pricing = secondary (Refer Screenshot)

However, I am unable to create a PO priced at KG

What am I missing?

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