Make sure you are in htdocs folder while executing the commands. I was trying to install Laravel in a Ubuntu virtual machine and got this error Your requirements could not be resolved to an installable set of packages. Problem 1 – phpunit/phpunit[7.5.0, …, 7.5.20] require ext-dom * -> it is missing from your system. Install or enable PHP’s dom extension. – Root composer.json requires phpunit/phpunit ^7.5 -> satisfiable by phpunit/phpunit[7.5.0, …, 7.5.20]. And To enable extensions, verify that they are