Note. The export option is only available to Business plan subscribers.
To export a page, click Page settings → Export
To export a website, click Site settings → Export
When exporting, you will receive a static HTML along with the images, css and js files.
Once the website is archived, you will receive a link to download it. Unzip the files and copy them to your server. Now you can open your site from your server, and it is independent from Tilda.
If your website requires some changes and updates, update it in Tilda first before exporting it again.
More about exporting: http://help.tilda.ws/export