Your requirements could not be resolved to an installable set of packages. Problem 1 - league/container is locked to version 2.4.1 and an update of this package was not requested. - league/container 2.4.1 requires php ^5.4.0 || ^7.0 -> your php version (8.1.2) does not satisfy that requirement. Problem 2 - coenjacobs/mozart is locked to version 0.5.1 and an update of this package was not requested. - coenjacobs/mozart 0.5.1 requires php ^7.2 -> your php version (8.1.2) does not satisfy that requirement. Problem 3 - dealerdirect/phpcodesniffer-composer-installer is locked to version v0.5.0 and an update of this package was not requested. - dealerdirect/phpcodesniffer-composer-installer v0.5.0 requires composer-plugin-api ^1.0 -> found composer-plugin-api[2.6.0] but it does not match the constraint. Problem 4 - phpunit/phpunit is locked to version 5.7.27 and an update of this package was not requested. - phpunit/phpunit 5.7.27 requires php ^5.6 || ^7.0 -> your php version (8.1.2) does not satisfy that requirement.