Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires phpunit/phpunit ^12.0 -> satisfiable by phpunit/phpunit[12.0.0, 12.0.x-dev]. - phpunit/phpunit[12.0.0, ..., 12.0.x-dev] require php >=8.3 -> your php version (8.2.27) does not satisfy that requirement. Problem 2 - Root composer.json requires orchestra/testbench 9.* -> satisfiable by orchestra/testbench[v9.0.0, ..., 9.x-dev]. - orchestra/testbench[v9.0.0, ..., v9.5.2] require phpunit/phpunit ^10.5 || ^11.0.1 -> found phpunit/phpunit[10.5.0, ..., 10.5.x-dev, 11.0.1, ..., 11.5.x-dev] but it conflicts with your root composer.json require (^12.0). - orchestra/testbench[v9.6.0, ..., 9.x-dev] require phpunit/phpunit ^10.5.35 || ^11.3.6 -> found phpunit/phpunit[10.5.35, ..., 10.5.x-dev, 11.3.6, ..., 11.5.x-dev] but it conflicts with your root composer.json require (^12.0).