CI4를 한번 설치 해 보려고 했는데...

처음에 

composer create-project codeigniter4/appstarter project-root -s rc

이렇게 해서 설치 하니 아래와 같이 문제점이 나오는데 이건 뭐가 뭔제라는건가요???

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Updating dependencies (including require-dev)

Your requirements could not be resolved to an installable set of packages.

  Problem 1

    - codeigniter4/framework v4.0.0-rc.3 requires ext-intl * -> the requested PHP extension intl is missing from your system.

    - codeigniter4/framework v4.0.0-rc.2.1 requires ext-intl * -> the requested PHP extension intl is missing from your system.

    - codeigniter4/framework v4.0.0-rc.2 requires ext-intl * -> the requested PHP extension intl is missing from your system.

    - codeigniter4/framework v4.0.0-rc.1 requires ext-intl * -> the requested PHP extension intl is missing from your system.

    - Installation request for codeigniter4/framework ^4@rc -> satisfiable by codeigniter4/framework[v4.0.0-rc.1, v4.0.0-rc.2, v4.0.0-rc.2.1, v4.0.0-rc.3].