Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires php-http/guzzle7-adapter ^1.0 -> satisfiable by php-http/guzzle7-adapter[1.0.0]. - php-http/guzzle7-adapter 1.0.0 requires php ^7.2 | ^8.0 -> your php version (7.1.33) does not satisfy that requirement. Problem 2 - Root composer.json requires http-interop/http-factory-guzzle ^1.2 -> satisfiable by http-interop/http-factory-guzzle[1.2.0]. - http-interop/http-factory-guzzle 1.2.0 requires php >=7.3 -> your php version (7.1.33) does not satisfy that requirement. Problem 3 - omnipay/tests[v4.0.0, ..., v4.0.2] require php ^7.3|^8 -> your php version (7.1.33) does not satisfy that requirement. - omnipay/tests[v4.1.0, ..., v4.1.2] require php ^7.2|^8 -> your php version (7.1.33) does not satisfy that requirement. - Root composer.json requires omnipay/tests ^4.0 -> satisfiable by omnipay/tests[v4.0.0, ..., v4.1.2].