Since There is no such things that unreal has provided just to take numbers as input here is an easy workaround in blueprints that you can use
- Create a Onchanged event on your input box.
- Convert the output text to string and check whether it is a numeric value or not(you can do so by a node called is numeric from kismet string library).
- Create a simple branch and in true just set the text of input box and in false leave it empty.
