get month in two digit in javascript date

JavaScript
let MyDate = new Date();
let MyDateString;

MyDate.setDate(MyDate.getDate() + 20);

MyDateString = ('0' + MyDate.getDate()).slice(-2) + '/'
             + ('0' + (MyDate.getMonth()+1)).slice(-2) + '/'
             + MyDate.getFullYear();("0" + (this.getMonth() + 1)).slice(-2)
Source

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