Hi guys

I would like to perform the Breusch-Pagan test for homoscedasticity. My question is what is the correct method to do this?
When i run the regression should i just type Hettest so the values are the fitted values of the Y-variable or should i type Hettest X1 X2 X3 etc.?
Ive seen videoes doing both things, so i am not sure what is correct?

Thanks a lot in advance