i want make a If the player is down, the model is destroyed
Assuming you're referring to the death of a player, you should use the Died function which you can find the documentation for here.
Here is an example of use that may help you:
player.Died:Connect(function() workspace:FindFirstChild"Model":Destroy(); end);
Closed as Non-Descriptive by TheeDeathCaster and TheHospitalDev
This question has been closed because its title or content does not adequately describe the problem you are trying to solve.
Please ensure that your question pertains to your actual problem, rather than your attempted solution. That is, you were trying to solve problem X, and you thought solution Y would work, but instead of asking about X when you ran into trouble, you asked about Y.
Why was this question closed?