From what I can see, sales is a local variable in the main(), and you are trying to access it in DetermineCommRate, and you have syntax errors in the definition of that function
def DetermineCommRate(sales):
Currently, you are passing sales to it, but not accepting it.
Also, your following line should be indented to run in the main()
if pay < 0:
    print("The salesperson must reimburse")
    print("the company")
And a syntax error in this line too
advancedPay = float(input("Advanced pay: "))
solved Indentation on python [closed]