Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires php ^7.3 but your php version (8.1.31) does not satisfy that requirement. Problem 2 - Root composer.json requires phpunit/phpunit 11 -> satisfiable by phpunit/phpunit[11.0.0]. - phpunit/phpunit 11.0.0 requires php >=8.2 -> your php version (8.1.31) does not satisfy that requirement.