How can I make a domain not be indexed by Google?

This can be done with the file robots.txt, this file can be created directly in the wwwroot folder of your hosting space.
In this file, only the following 2 lines need to be inserted:

User-agent: Disallow
: /This


ensures that all search engines skip this website.

If you have any further questions you can always check if there is someone on the online chat.
Or you can create a ticket for this in the customer panel.

keywords: robot robots.txt text