If you did everything according to the instructions and the domain is not working:
1. Refresh the page several times. Browsers (especially Google Chrome) store old versions of the page in the browser cache, so domain may be connected correctly but changes are not visible.
2. Make sure that you have specified the domain in the Site Settings, saved the settings and published whole pages.
3. Make sure that you have only one A record and it points to188.8.131.52
4. If you type a link starting from www in the address bar (e.g. www.mysite.com), make sure that you have created a CNAME record for «www» host and it points to tilda.ws.
5. If you see a warning that your site is unsafe, it means that you haven't configured a HTTPS in the Site Settings. Follow the «How to add a HTTPS to a connected domain» article. If you see that warning from search engine results you should also turn off a «Use HTTPS scheme...» checkbox in the Site Settings → More.