Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires illuminate/support ^8.12|^9.0|^10.0|^11.0|^12.0 -> satisfiable by illuminate/support[v8.12.0, ..., 8.x-dev, v9.0.0-beta.1, ..., 9.x-dev, v10.0.0, ..., 10.x-dev, v11.0.0, ..., 11.x-dev, v12.0.0, ..., 12.x-dev]. - Root composer.json requires orchestra/testbench 11.* -> satisfiable by orchestra/testbench[11.x-dev]. - laravel/framework dev-master requires php ^8.4 -> your php version (8.3.30) does not satisfy that requirement. - orchestra/testbench 11.x-dev requires laravel/framework ^13.0.0 -> satisfiable by laravel/framework[13.0.x-dev (alias of dev-master), 13.x-dev]. - Only one of these can be installed: laravel/framework[dev-master, 13.x-dev], illuminate/support[v8.12.0, ..., 8.x-dev, v9.0.0-beta.1, ..., 9.x-dev, v10.0.0, ..., 10.x-dev, v11.0.0, ..., 11.x-dev, v12.0.0, ..., 12.x-dev]. laravel/framework replaces illuminate/support and thus cannot coexist with it. - laravel/framework 13.0.x-dev is an alias of laravel/framework dev-master and thus requires it to be installed too. - Only one of these can be installed: laravel/framework[dev-master, 13.x-dev], illuminate/support[v11.0.0, ..., 11.x-dev, v12.0.0, ..., 12.x-dev]. They all replace spatie/once and thus cannot coexist.