PHP Composer extension is not accessible in Plesk after Composer upgrade to v2.0: Package plesk/composer-command-info has a PHP requirement incompatible with your PHP version, PHP extensions and Composer version

Symptoms

• When accessing Plesk > Domains > example.com > PHP Composer page, the following error message is displayed:

  PLESK_ERROR: Could not update the integration plugin
  Changed current directory to /var/www/vhosts/example.com/.composer
  [InvalidArgumentException]
  Package plesk/composer-command-info at version ~1.0.2 has a PHP requirement incompatible with your PHP version, PHP extensions and Composer version

• PHP Composer extension of version 1.1.0 or later is installed on the server. It can be checked in Extensions > My Extensions > PHP Composer.

Cause

The older version of Composer is used by default despite Composer was updated to v2.0:

# composer --version
Composer version 2.0-dev

Resolution

1. Log into Plesk.

2. Go to Extenions > My Extensions > Panel.ini Editor > Open.

   Note: If Panel.ini Editor extension is not installed, install it from the Extensions menu in Plesk.

3. Switch to the Editor tab.

4. Specify the Composer and plugin versions by adding the lines below at the end of the file as below:

   CONFIG_TEXT: [ext-composer]
   commandInfoPluginVersion = "~1.1.0"
   composerVersion = '2'