How to change Follow Mode Pro-rata


I set up a Demo Account with $25,000 funds a week ago.
In the set up, when I selected a trader, i elect pro-rate with 1:1 ratio.

Throughout my first week experiencing zulu trade, I noticed that my Utilised Margin is no more than $1000. Leaving Available margin of $24,000.

How can I increase the utilised margin to at around $10,000 (10x), leaving untilised margin of around ($15,000).

I have entered into setting tab. But there is no option there that I can use to multiply my lot allocation 10x than the currently utilised.

Appreciate some guidance. Thank you.