Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires phpunit/phpunit 11.* -> satisfiable by phpunit/phpunit[11.0.0, ..., 11.5.x-dev]. - phpunit/phpunit[11.0.0, ..., 11.5.x-dev] require php >=8.2 -> your php version (8.1.33) does not satisfy that requirement.