Mad Level Manager Unlock Level

Hi there, I have recently purchased Mad Level Manager through the unity asset store and I cant seem to make the levels unlock. In my game the player has to complete a level in 10 seconds. By completing the level in 8 second the player get 3 stars, completing the level in 9 seconds will give you 2 start and by completing the level in 10 second will give you 1 star. Getting any number of stars should unlock the next level. unfortunately I am unable to get this to work and I am fairly new the the programming world. I would very much appreciate it if you could help me with my query

Many thanks Reece