[FYI] Automatically put 'spaces' for credit/debit card inputs.

[Wikiwi]

This is a quick tutorial on how to format user input for credit/debit cards.

First, we would need to add Header & Footer on your submission form and uncheck HTML editor. Once, done kindly put the code below inside the Footer.
 

<script>
var input = document.getElementById("textfield_ID");
var ctr = 0;
input.unsafe = function () {

    var key = event.keyCode || event.charCode;
    
    if (key == 8 || key == 46){
        if(input.value.length > 0){
            ctr = input.value.length-1;
        }
    }
    else {
        ctr = input.value.length+1;
        if(((ctr % 5) == 0) && ctr <19){
            input.value += ' ';
        }
    }
}
</script>

Once that is done, don't forget to set the maximum character limit for your Credit/Debit card field to 19. 

This should result to something like this: