title: I am missing simplexml on my ubuntu machine but I can't download it
body: <p>so I get the following error while installing Pterodactyl panel:</p>
  <pre><code>Problem 1
  - Installation request for aws/aws-sdk-php ^3.156 -&gt; satisfiable by aws/aws-sdk-php[3.156.0].
  - aws/aws-sdk-php 3.156.0 requires ext-simplexml * -&gt; the requested PHP extension simplexml is missing from your system.
  
  
  
  To enable extensions, verify that they are enabled in your .ini files:
      - /etc/php/7.4/cli/php.ini
      - /etc/php/7.4/cli/conf.d/10-mysqlnd.ini
      - /etc/php/7.4/cli/conf.d/10-opcache.ini
      - /etc/php/7.4/cli/conf.d/10-pdo.ini
      - /etc/php/7.4/cli/conf.d/20-bcmath.ini
      - /etc/php/7.4/cli/conf.d/20-calendar.ini
      - /etc/php/7.4/cli/conf.d/20-ctype.ini
      - /etc/php/7.4/cli/conf.d/20-exif.ini
      - /etc/php/7.4/cli/conf.d/20-ffi.ini
      - /etc/php/7.4/cli/conf.d/20-fileinfo.ini
      - /etc/php/7.4/cli/conf.d/20-ftp.ini
      - /etc/php/7.4/cli/conf.d/20-gettext.ini
      - /etc/php/7.4/cli/conf.d/20-iconv.ini
      - /etc/php/7.4/cli/conf.d/20-json.ini
      - /etc/php/7.4/cli/conf.d/20-mbstring.ini
      - /etc/php/7.4/cli/conf.d/20-mysqli.ini
      - /etc/php/7.4/cli/conf.d/20-pdo_mysql.ini
      - /etc/php/7.4/cli/conf.d/20-phar.ini
      - /etc/php/7.4/cli/conf.d/20-posix.ini
      - /etc/php/7.4/cli/conf.d/20-readline.ini
      - /etc/php/7.4/cli/conf.d/20-shmop.ini
      - /etc/php/7.4/cli/conf.d/20-sockets.ini
      - /etc/php/7.4/cli/conf.d/20-sysvmsg.ini
      - /etc/php/7.4/cli/conf.d/20-sysvsem.ini
      - /etc/php/7.4/cli/conf.d/20-sysvshm.ini
      - /etc/php/7.4/cli/conf.d/20-tokenizer.ini
      - /etc/php/7.4/cli/conf.d/20-zip.ini
    You can also run `php --ini` inside terminal to see which files are used by PHP in CLI mode.
  </code></pre>
  <p>but then when doing sudo apt-get install -y php-simplexml</p>
  <p>it gives me this:</p>
  <pre><code>    Reading package lists... Done
  Building dependency tree       
  Reading state information... Done
  Package php-simplexml is a virtual package provided by:
    php7.4-xml 7.4.10-1+ubuntu20.04.1+deb.sury.org+1
    php7.3-xml 7.3.22-1+ubuntu20.04.1+deb.sury.org+1
    php7.2-xml 7.2.33-1+ubuntu20.04.1+deb.sury.org+1
    php7.1-xml 7.1.33-17+ubuntu20.04.1+deb.sury.org+1
    php7.0-xml 7.0.33-30+ubuntu20.04.1+deb.sury.org+1
    php5.6-xml 5.6.40-30+ubuntu20.04.1+deb.sury.org+1
  You should explicitly select one to install.
  
  E: Package 'php-simplexml' has no installation candidate
  </code></pre>
  <p>what can I do?</p>
  <p>I'm new to ubuntu and have no clue of what to do</p>