The submitted journal makes the filling of invoice information unnecessary. According to the relevant information inquired, filling in the invoice information does not mean that the submitted journal has been hired. Filling in invoice information is a normal financial operation, and journals need to confirm whether the author needs to issue invoices for corresponding financial treatment. Whether to hire or not is decided by the editor or reviewer according to the quality and suitability of the paper, and usually the author is clearly informed in the employment notice.