Transfer website from test.domainname.com to domainname.com
OR
Transfer website from mydomainname.com to domainname.com

1. Make PHP compatible
Make sure domainname.com has PHP 7.3 or 7.4

2. Copy docroot of test.domainname.com to domainname.com
Go to cPanel -> File Manager

/home/{user}/{test.domainname.com}/
(Select all -> Copy)

to
/home/{user}/public_html/

3. Move content 
Go to cPanel -> File Manager

/home/{user}/rvsitebuildercms/{test.domainname.com}

Rename to
/home/{user}/rvsitebuildercms/{domainname.com}

4. Edit .env content
Go to cPanel -> File Manager

/home/{user}/rvsitebuildercms/{domainname.com}/.env

(where to find .env)

APP_NAME={domainname.com}

APP_URL={https:domainname.com}

DOCUMENT_ROOT=/home/{user}/public_html

5. Clear cache

/home/{user}/rvsitebuildercms/{domainname.com}/storage/framework/cache/data/
(Select all -> Delete)

6. Access Rvsitebuider 7 for domainname.com to continue edit your website.

DONE