Can't create a custom repeat action. (Every last day of weekdays per month)

I usually use the apple reminder and Google's task, and the custom repeat action works fine. But here on Microsoft To Do app the custom is too simple. When I try to customize the repeat action, and I choose "MONTH" it just gives how many months. But there is no custom actions like at the last Friday of the month, or the last day of a weekday of the month. 

Someone can help me please?