You can change content of this html:
Default pages are located in following locations:
On Linux: the
HTTPD_VHOSTS_D/default/htdocs
(non-SSL) and
HTTPD_VHOSTS_D/default/httpsdocs
(SSL) folders respectively.
On Windows:
%plesk_vhosts%\default\htdocs
(non-SSL) and
%plesk_vhosts%\default\httpsdocs
(SSL) folders.
HTTPD_VHOSTS_D /var/www/vhosts
Make a html file Redirect all domains to a certain domain