HI @sruthesanju
Another Method is like you can pass your input string into the expression like in the image
DateTime.ParseExact("01/15/2022","MM/dd/yyyy",System.Globalization.CultureInfo.InvariantCulture).AddMonths(-1).ToString("MM/dd/yyyy")

Here Now.addmonths(-1) will give the only the previous month date not your required output

Regards
Gokul