In order to use your owned domain and connect it to your website builder, you should follow the steps:

1. Connect to your domain registrar panel;
2. Choose the domain you want to connect to Website Builder;
3. Create new or edit existing A record and point it to the server:

185.76.64.223

That is it, you might need to wait some time (usually up to 1 hour) for DNS propagation, but after this time, your domain should be connected to the Website Builder correctly.

Note. If you have a registered domain at Hostens, you may check this article Working with DNS Manager.