If you want to claim the biggest bonus, you need to figure out a solution with your own funds. Try speaking to their customer support in order to try and find some solutions.
When you haven't heard of it before, it may just be good to not get into it. It's been a golden rule already not to try on casinos that are not really tested by individuals here.
As for OP, showing this here like you wanted to as for loan will end with a dispute. One scenario I could think of is that the casino will charge you for cheating in the bonuses and you will not be able to withdraw them and the person you took a loan loses.