Problemas ao criar o projeto

Boa tarde, Estou tentando criar o projeto com o código composer create-project symfony/skeleton consultorio-alura. e não baixa tudo. aparece a mensagem 'Your requirements could not be resolved to an installable set of packages'

` Problem 1

- symfony/framework-bundle v5.1.2 requires ext-xml * -> the requested PHP extension xml is missing from your system.
- symfony/framework-bundle v5.1.1 requires ext-xml * -> the requested PHP extension xml is missing from your system.
- symfony/framework-bundle v5.1.0 requires ext-xml * -> the requested PHP extension xml is missing from your system.
- Installation request for symfony/framework-bundle * -> satisfiable by symfony/framework-bundle[v5.1.0, v5.1.1, v5.1.2].```

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-opcache.ini
- /etc/php/7.4/cli/conf.d/10-pdo.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-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

You can also run php --ini inside terminal to see which files are used by PHP in CLI mode.

e sempre que uso o ' -t public' aparece a mensagem "Directory public does not exist."

Poderia me ajudar??