generate rissert drum

When I add a track and generate the risset drum I get just one beat what am I doing wrong?

Probably nothing. The Risset Drum generator produces one “boing” sound.
If you wish to repeat the sound many times, generate one “boing” then, while the sound is selected, “Effect menu > Repeat…” (about 2/3rds of the way down the list), and enter the number of times you want to repeat the sound.

boing! I got it thanks