JSFiddle - React, Tailwind, and code Playground

HTML

<fieldset id="selbstabholung">
<label><input name="a" type="radio" value="Ja" />Ja</label>
<label><input name="a" type="radio" value="Nein" />Nein</label>
</fieldset>

JavaScript

registerRadioListener("selbstabholung", radioChanged);

function registerRadioListener(id, func) {
   var set = document.getElementById(id);
   if (set !== null)
      set.querySelectorAll("input").forEach(function(r) {
         r.addEventListener("change", func);
      });
}

function radioChanged(evt) {
   var rb = evt.target;
   alert(rb.name+"="+rb.value);
}