Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires php ^7.4 || ^8.0 but your php version (7.1.33) does not satisfy that requirement. Problem 2 - Root composer.json requires phpunit/phpunit ^9.6.17 -> satisfiable by phpunit/phpunit[9.6.17, 9.6.x-dev]. - phpunit/phpunit[9.6.17, ..., 9.6.x-dev] require php >=7.3 -> your php version (7.1.33) does not satisfy that requirement. Problem 3 - guzzlehttp/psr7[2.0.0-beta1, ..., 2.6.x-dev] require php ^7.2.5 || ^8.0 -> your php version (7.1.33) does not satisfy that requirement. - Root composer.json requires guzzlehttp/psr7 ^2.0 -> satisfiable by guzzlehttp/psr7[2.0.0-beta1, ..., 2.6.x-dev].