position sizing and determining leverage with kelly formula

i want to ask something about kelly formula.how can i use kelly formula in order to find leverage??i know kelly formula it finds optimum position size.but what about leverage??
if ı have a system which has positive expectancy is it good to use kelly formula with any leverage??i mean does it matter if ı use 1:1 leverage or 1:10 or 1:50 with my kelly formula??

for example my kelly formula equals to 0,30 and my initial capital 10000
so i will invest 3000.but which leverage will i use?
1:1 1:10 1:50 which one??
how can i determine my leverage??

Check out Money Management Using the Kelly Criterion