It is customary in China to use tax inclusive price in PO quotation. In SAP, negative tax backwash (calculate negative tax through tax rate) should be maintained in the condition type of purchase order. Can refer to https://blogs.sap.com?p=313
The current problem is how to maintain the calculation process of the calculation scheme
(102430 Set Alternative Calculation of Condition Amount).Below 2 is a screenshot of the above post.