All commands come back with this error, even just the 'composer' command.
If I try to run the composer update "drupal/core-*" --with-all-dependencies with the super user account it works fine, with my other plesk account if I run this command then it comes back with the error.
I can run composer fine from the superuser account.
From any other account I get the following error message:
phpenv: composer: command not found
I'm guessing it's some sort of permissions issue or something, but I don't have a clue how to fix this.