Navigate to
Grand Theft Auto V > scripts > Superman V2 script files
and drag and drop "Movie Sounds" into the "Superman V2 script files" folder

Note 1: The Suit .ini that is given to you in this zip file is needed for sounds and props to work.
Note 2: In the movies (BvS, ZSJL) Superman has one sound for each intesities of his laser. so in the default "Movie Sounds" Folder, laser_normal and laser_blast have the same
sounds. all though a different laser_blast sound effect is given to you in the "Optionals" folder.