In STP accounts, the Margin Call is triggered when the Margin Level (Equity to Margin ratio) is less than 50% (i. e. the equity of your trading account is equal to the margin used to open the positions).

A losing position is stopped out (closed by broker automatically) when the Margin Level of an account is less than 30% (i. e. the equity is less than 30% of the margin used to open a trade).

The full calculation of the equity/margin ratio for the stopped out positions is available in the MetaTrader. Open Terminal window, Account history tab, column Comment. If you do not see the Comment column in your MetaTrader Account History, right-click on the closed position and select Comment.

You can check Margin level in the MetaTrader → Terminal window → Trade tab.