Buying in-app

Good day there, I am a Binance consumer since this summer time and since then I've added some money on my account, but i also added small quantities a number of occasions (underneath the traditional limit which is $15), however I tried a number of moments in the past so as to add a smaller amount again who needs to get began with crypto on futures, it didn't work, it says minimum is $15, but I personally have a couple of transactions with less than $15 so I do know you'll be able to/might truly do it. Can anybody tell me methods to do it or tell me it it still works?