With NPrinting 17+ it is possible to distribute reports to a hard drive folder which can be read by the Qlik FTP/SFTP Web Connector for an FTP upload operation.
Since you trigger both of these events through Qlik load script, you can chain both events to occur sequentially and solve the problem of having NPrinting FTP reports to an FTP server.
This is a potential replacement solution for customers upgrading from NPrinting 16 where FTP was a product feature.
*Note: Please use Qlik Web Connectors November 2018 or earlier for this solution . Qlik Web Connectors June 2019 contains a bug that is currently under investigation and is unsuitable for this use case until further notice.