Managed accounts reach stop out level when your equity falls to less than 30% of the used margin. At this point, your account will reach the stop out level and will be detached from the program.
Please make sure that you fund your account well in advance to make sure you can support your margin requirements.
As a reminder, please note that the Margin level = Equity / Used margin * 100%
You can add the stop out level you choose on your managed account based on the account's equity, you can find more details here.