To Install and remove PHP on Virtualmin

sudo dnf install php81-php-{cli,fpm,pdo,gd,mbstring,mysqlnd,opcache,curl,xml,zip,intl,sodium,ldap,smbclient,ftp,imap,bcmath,gmp,exif,apcu,memcached,redis,imagick,pcntl,phar,xmlrpc}

Replace 81 with your required version, e.g. 84, 85 etc. 

To remove a specific version, you'd use 

sudo dnf remove php81-php-*

and to list what you've got installed, go with 

dnf list installed | grep php81

Don't forget to clean up afterwards with

sudo dnf autoremove