Can someone who has help me please?
Apparently, you need a serial code to install it that can be found on page 3 of the user manual, which I do not own.
Just a heads up, you might want to prepare to update this soon. It suffers from no-progress bug that is currently under rapid debugging.
Scheduled to be fixed on May 1st at 22:00 JST. 聖騎士リアナ