Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires phpunit/phpunit ^12.2 -> satisfiable by phpunit/phpunit[12.2.0, ..., 12.2.6]. - phpunit/phpunit[12.2.0, ..., 12.2.6] require php >=8.3 -> your php version (8.2.28) does not satisfy that requirement.