Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires illuminate/contracts ^12.0 -> satisfiable by illuminate/contracts[v12.0.0, ..., 12.x-dev]. - Root composer.json requires pestphp/pest-plugin-laravel ^4.0 -> satisfiable by pestphp/pest-plugin-laravel[v4.0.0, 4.x-dev]. - pestphp/pest-plugin-laravel[v4.0.0, ..., 4.x-dev] require laravel/framework ^11.45.2|^12.25.0 -> satisfiable by laravel/framework[v11.45.2, ..., 11.x-dev]. - Conclusion: don't install illuminate/contracts v12.0.0 (conflict analysis result) - Only one of these can be installed: laravel/framework[v11.0.0, ..., 11.x-dev], illuminate/contracts[v12.0.0, ..., 12.x-dev]. laravel/framework replaces illuminate/contracts and thus cannot coexist with it.