Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires phpunit/phpunit ^12.0.0 -> satisfiable by phpunit/phpunit[12.0.0, ..., 12.1.x-dev]. - phpunit/phpunit[12.0.0, ..., 12.1.x-dev] require php >=8.3 -> your php version (8.2.28) does not satisfy that requirement.