JSFiddle - React, Tailwind, and code Playground

JavaScript

var url = 'http://website.com/generate-token/#access_token=ya29.AHES6ZTJwb9lzb0lua81oHa47-8ImcJf-8qE-02kIn8JcgEv&token_type=Bearer&expires_in=3600';

function getParameterByName(name, url) {
    name = name.replace(/[\[]/, "\\\[").replace(/[\]]/, "\\\]");
    var regex = new RegExp("[\\?&#]" + name + "=([^&#]*)"),
        results = regex.exec(url);
    return results == null ? "" : decodeURIComponent(results[1].replace(/\+/g, " "));
}

alert(getParameterByName('access_token', url));