All modern marketplaces themselves provide invoices with tax information, invoice PDF and AWB with logistics provider
Brand E-Commerce Portal
Most brand portals run on e-commerce software like Hybris, Salesforce Commerce Channel, Shopify etc. All these systems provide build in functionality for tax computations, invoicing, logistics, order splitting and order routing. Thus, in this case, it is expected that the brand portal will provide APIs to fetch tax invoice, invoice PDF and AWB (with logistics provider)
In case of ERP, the client will already have different tax rules also custom invoicing format fed into the ERP. It is imperative that the tax calculation matches to the right decimal place (as per the tax rules fed into the ERP).
Hence, for B2B orders created via an ERP, it is expected that the ERP will provide APIs to fetch tax invoice, invoice PDF and AWB (with logistics provider).