Error:
*The entered value [300.0] of the property [sumCelkem] differs from the calculated value
[0.0] [00000001/15]: sumCelkem - 300.0*
VAT needs to be broken down properly. If you enter only sumCelkem, Flexi attempts to calculate the remaining values without any tax information, which is why the result is zero.
For the standard VAT rate, the required fields include, for example: Total Base [CZK], Standard VAT Base [CZK], and Standard VAT [CZK].
For more information about the available fields, see https://demo.flexibee.eu/c/demo/faktura-vydana/properties
If the invoice is a line-item-free invoice, you must specify in the XML/JSON file that the document is of the line-item-free type.