Solution : https://service.sap.com/sap/support/notes/414177 (SAP Service marketplace login required)
Key words :
additional key words bseg-wmwst, 'basic data' tab page, 'tax' tab page, fi enjoy transaction, prerequisites program design, enter tax amount, bseg-mwskz, tax amount, program assumes, entering invoices
Related Notes :
856749 | FB60: Displaying calculated taxable value on tax tab page |