Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires typo3/testing-framework dev-main#286e60f918b88cdc6ff4c29b89c6fe67bd80a543 -> satisfiable by typo3/testing-framework[dev-main]. - typo3/testing-framework dev-main requires typo3/cms-core 13.*.*@dev -> found typo3/cms-core[dev-main, v13.0.0, ..., 13.4.x-dev (alias of dev-main)] but it conflicts with your root composer.json require (^12).