New ticket page custom validation script

Product Customize x Workflows
1

Good evening,

I’m trying to add some custom validation to a field in the New Ticket page of one of my portals.

I want a string containing numbers only.
This is the script:

window.onload = function () {
    console.log("Window loaded");
    document.getElementById("ticket-field-26000211954").onclick = () => {
        setTimeout(() => { console.log('Wait a bit just to be sure'); }, 1000);
        const pIva = document.getElementById("26000211957");
        pIva.setAttribute("pattern", "^[0-9]+$");

        pIva.onkeyup = () => {
            let invalid = !new RegExp('^[0-9]+$').test(pIva.value);
            //pIva.setAttribute("invalid", invalid.toString());
            //pIva.setAttribute("aria-invalid", invalid.toString());
            //pIva.ariaInvalid(invalid);
            if (invalid) {
                console.log("Adding error")
                pIva.classList.add("error");
            } else {
                console.log("Removing error")
                pIva.classList.remove("error");
            }
        };
    };
};

I want the form to become invalid when this field contains any number.
I’m able to set a pattern, but seems to have no use in Freshservice froms, same with adding classes.

image
image1210×83 6.54 KB

I even tried to use ariaInvalid() (out of desperation) but doesn’t work.

Did anyone else try to do this kind of cusom validation? Did you have success?