Is this a custom application or something we can check the documentation for? I’m not having any luck googling the error with “addfunds.php”.
And, if you haven’t tried PHP 7.3, it may be worth a shot. As long as you install it with the package manager, it’s easy to add and then remove later if it turns out you don’t need it.
Docs for that are here: Multiple PHP Versions – Virtualmin
The Ondrej repo has php7.3 package version 7.3.33 for Ubuntu 20.04, so that’s the one you’d need to install. e.g. once you’ve setup the repos as covered by that guide, you can do:
apt-get install php7.3-{cgi,cli,fpm,pdo,gd,mbstring,mysqlnd,opcache,curl,xml,zip}
And, then run Re-check Configuration in Virtualmin and then you’ll be able to select a different PHP version for this Virtual Server.