https://www.probono-oneworld.de/assets/javascripts/components/sections/donate.js

1document.querySelectorAll('.donate .reiter li').forEach(element => {
2    element.addEventListener('click', setDonateBox);
3});
4
5function setDonateBox(element) {
6    document.getElementById("form-abo").reset();
7    document.getElementById("form-single").reset();
8    clickedElement = (element.currentTarget.getAttribute('data-attribute'));
9    document.querySelectorAll('.donate .reiter li').forEach(element => {
10        element.classList.remove('active');
11    })
12    element.currentTarget.classList.add('active');
13
14    document.querySelectorAll('.donate .donate-items .item').forEach(element => {
15        element.classList.remove('active');
16    })
17
18    document.getElementById(clickedElement).classList.add('active');
19}