I am having trouble getting Roundcube 1.6.1 to work on my server. I believe some pre-existing configuration on my server may interfere with Roundcube but I am unsure. Here is what I have set up so far:

1. I have Odoo installed on my server within a Python3 virtual environment hosted on the primary domain.
2. Odoo is running on Apache2 web server on port 8069 (default) and is reverse proxied from its virtual host configuration so it is accessible on ports 80/443.

I have downloaded Roundcube and installed the following PHP extensions:

sudo apt install php-net-ldap2 php-net-ldap3 php-imagick php8.1-common php8.1-gd php8.1-imap php8.1-mysql php8.1-curl php8.1-zip php8.1-xml php8.1-mbstring php8.1-bz2 php8.1-intl php8.1-gmp php8.1-redis

I have also configured an Apache2 Virtual Host for Roundcube:

<VirtualHost *:80>
  ServerName mail.MyDomain.com
  DocumentRoot /var/www/roundcube/

  ErrorLog ${APACHE_LOG_DIR}/roundcube_error.log
  CustomLog ${APACHE_LOG_DIR}/roundcube_access.log combined

  <Directory />
    Options FollowSymLinks
    AllowOverride All
  </Directory>

  <Directory /var/www/roundcube/>
    Options FollowSymLinks MultiViews
    AllowOverride All
    Order allow,deny
    allow from all
  </Directory>

</VirtualHost>

However, when I visit mail.MyDomain.com, I receive the following error message: "Unsupported PHP version. Required PHP >= 7.3." The subdomain works and the Roundcube favicon appears, which means the domain configuration is correct and Apache2 is reading from the correct directory. Therefore this error implies an issue with my Apache2 PHP version.

I tried installing libapache-mod-php8.1 and enabling it. However, upon reloading my website, both the mail subdomain and the Odoo primary domain broke, so I had to disable it and reload again (sudo a2dismod).

How should I configure Roundcube to work with mail.MyDomain.com? Any advice is appreciated, thanks