btcpayserver/BTCPayServer/wwwroot/main/utils.js

function delegate(eventType, selector, handler, root) {
    (root || document).addEventListener(eventType, function(event) {
        const target = event.target.closest(selector);
        if (target) {
            if (handler.call(this, event) === false) {
                event.preventDefault();
            }
        }
    });
}