Vendor purchase "Purchase" button is disabled?

[Claire Ashdown2]

I am trying to use the Hardware Inventory Stock Order catalog item in a test environment. I have generated the "Source Request Items" catalog task, however when I use "Source request" in the Hardware Asset Workspace to fulfill the request, the Vendor purchase "Purchase" button is disabled. Troubleshooting through UI Builder, I found that the Purchase button for vendor purchase will be greyed out unless com.snc.sn_spend_asset ("Asset Management Integration for Sourcing and Procurement Operations") is enabled and the user has the sn_spend_asset.spo_shopper role. This data for whether the button will be selectable or not (this plugin and role check) is retrieved through ProcSourceRequestManager.getRequestItemsForWorkspace(input.requestId).

Am I understanding correctly that having HAM alone will not allow you to create a Vendor PO through the Hardware Inventory Stock Order catalog item, you must also have Asset Management Integration for Sourcing and Procurement Operations? So essentially, with HAM alone, the Vendor purchase "Purchase button" will be visible but completely unusable?

This is similar to https://www.servicenow.com/community/ham-forum/sourcing-task-vendor-purchase-button-not-working/m-p/... except it is using the Hardware Inventory Stock Order catalog item, not an individual model published to the catalog. I tried the solution to ensure the product model's manufacturer company record had Vendor set to true, and that did not make the "Purchase" button available.