How do i make this box appear?

Hey,
Lets say that you have two radio buttons:


The value of Yes is set to “true” and the value of No is set to false. You should add event listener to the radio buttons group:

$w.onReady(function () {
    $w('#radioGroup1').onChange(()=>{
         if(($w('#radioGroup1').value)){
            $w('#textboxId').show();
         }
         else{
            $w('#textboxId').hide();
         }           
    })
});

I hope it’s clear.

Best,
Tal.