If for some reason you need to change the domain and want to contain the existing site, it's not a problem, it can be done. There are several reasons for switching from one domain to another or changing the hosting. Perhaps the provider to whom you were registered has stopped working, you may not be satisfied with their service, or you have a need for a cheap but faster and more reliable hosting.
However, domain changes are somewhat rarely decided, and even not recommended, mostly because Google has already indexed your site as such and has already been placed in certain positions, and if you change a domain, you are moving everything from scratch to Google, u. In that case, it is mandatory to redirect the site from the old domain to the new one, since your old site will continue to appear in searches and to keep as many positions so long, until the new site indexes and does not play on a thick list with the competition. You can not do these jobs yourself, so you can contact us for help.