Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires pestphp/pest-plugin-browser ^4.3.1 -> satisfiable by pestphp/pest-plugin-browser[v4.3.1, 4.x-dev]. - pestphp/pest-plugin-browser[v4.3.1, ..., 4.x-dev] require pestphp/pest ^4.4.5 -> satisfiable by pestphp/pest[v4.4.5, ..., 4.x-dev] from composer repo (https://repo.packagist.org) but pestphp/pest dev-1073e51a6193a3f5ce4ad062903cd86b57533cc0 is the root package and cannot be modified. See https://getcomposer.org/dep-on-root for details and assistance.