Web View for "Purchase Order Item" Child Table?

Is there a way to allow a Web View, that a Guest can access, for Child Tables, specifically the Purchase Order Item DocType?

I ask because it is easier to create a Web View than trying to use the DocType Layout tool.

Background
Trying to make a Web Form for an internal site where by a Guest user can create a Purchase Order entry.
I can make a Purchase Order view that is functional, as the Guest user role has been added to the Purchase Order role permissions.
The issue I have is that when adding an Item to the Purchase Order Item child table, I cannot double click and select an item from the list. If logged in I can select an item, but the associated info like description and UoM do not populate.

Is there some hidden permissions or options that can make a Purchase Order Item populate correctly to a guest user?

Thanks,
Paul