Your requirements could not be resolved to an installable set of packages. Problem 1 - phpunit/phpunit[11.3.5, ..., 11.4.x-dev] require php >=8.2 -> your php version (8.1.29) does not satisfy that requirement. - Root composer.json requires phpunit/phpunit ^11.3.5 -> satisfiable by phpunit/phpunit[11.3.5, 11.3.6, 11.3.x-dev, 11.4.x-dev].