since phpmyadmin is not working properly in hestiacp I tried to install pgadmin4 and really struggled due to a silly mistake. So this for any one who wants to install pgadmin4.
follow official guide to install pgadmin4
https://www.pgadmin.org/download/pgadmin-4-apt/
cd /etc/apache2/
cp conf-enabled/pgadmin4.conf conf.d/
restart apache that’s it.
now show it should work http://{domain}/pgadmin4