インストールのときの「Username」と「Password」がわからない。
ubuntu@ip-172-31-45-120:/var/www/html$ sudo composer create-project --repository-url=https://repo.magento.com/ magento/project-community-edition /var/www/html/
Do not run Composer as root/super user! See https://getcomposer.org/root for details
Creating a "magento/project-community-edition" project at "./"
Warning from repo.magento.com: You haven't provided your Magento authentication keys. For instructions, visit
https://devdocs.magento.com/guides/v2.3/install-gde/prereq/connect-auth.html
Authentication required (repo.magento.com):
Username:
Password:
Warning from repo.magento.com: You haven't provided your Magento authentication keys. For instructions, visit
https://devdocs.magento.com/guides/v2.3/install-gde/prereq/connect-auth.html
Warning from repo.magento.com: You haven't provided your Magento authentication keys. For instructions, visit
https://devdocs.magento.com/guides/v2.3/install-gde/prereq/connect-auth.html
Warning from repo.magento.com: You haven't provided your Magento authentication keys. For instructions, visit
https://devdocs.magento.com/guides/v2.3/install-gde/prereq/connect-auth.html
In RemoteFilesystem.php line 746:
Invalid credentials for 'https://repo.magento.com/packages.json', aborting.
create-project [-s|--stability STABILITY] [--prefer-source] [--prefer-dist] [--repository REPOSITORY] [--repository-url REPOSITORY-URL] [--add-repository] [--dev] [--no-dev] [--no-custom-installers] [--no-scripts] [--no-progress] [--no-secure-http] [--keep-vcs] [--remove-vcs] [--no-install] [--ignore-platform-reqs] [--] [ [
[]]]
ubuntu@ip-172-31-45-120:/var/www/html$
この「Username」と「Password」は、MangentのMarketplaceで、「Create A New Access Key」で発行するAccess Keyがこれにあたり、Public KeyとPrivate Keyがユーザ名とパスワードにあたる。（いや、これ、わかりにくい）
Username ＝ Public Key Password ＝ Private Key