How to group fright charges sent from Order Management to Account Receivables

Summary:

We are facing an issue in grouping the freight charges coming from Order Management to Account Receivables and the grouping rule is based on shipment number. (Interface Line Attribute 7).

Content (required):

Our client has a requirement to charge tax on freight lines. To achieve this, we defined freight as a separate item, When we import the sales orders into receivables, it creating two different invoices in receivables, one for the sales order line and the other for the freight line.

Here we define freight as a separate item to calculate the tax on that, and that is not a shippable line. This may be the reason it creates two invoices when we import. If yes, can you help us group the sales order line with the freight line while importing from Order management.