Hello,

These websites have Deprecated CSS classes and the structure is a bit different. You need to replace

var offerteAanvragenTab = document.querySelector('.woocommerce-tabs .wd-accordion-item.wd-tab-wrapper > .tab-title-offerte_aanvragen_tab');

with this

var offerteAanvragenTab = document.querySelector('.woocommerce-tabs .wd-accordion-item > .tab-title-offerte_aanvragen_tab');

Kind Regards