You can't. Because freight forwarders are generally export freight forwarders, export value-added tax has been exempted, and export input tax has been refunded to you, which means that you have not paid any tax in the export link. This is a discount for export goods.

For domestic sales, there are not so many preferential policies in domestic sales, and it is impossible to exempt from VAT. It is also impossible to refund the tax, so it is unreasonable for you to use the input tax of export to deduct the output tax of domestic sales, and the state does not allow it. If this situation is found, it is defined as tax evasion and the punishment is quite heavy.