How do I set a random animation frame on spawn for a game that uses a wave system?

I am making a game that has minigames, and i need to have the sprite to spawn with a random animation frame at the start of each wave

On created - set animation frame to round(random(x,y)) where x and y are the upper and lower limits and round ensures it is a rounded number.

On created - set animation frame to round(random(x,y)) where x and y are the upper and lower limits and round ensures it is a rounded number.

how do i do 'On created'and where do i put it?

A condition under the Sprite object

oh okay, thanks!