Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires typo3/cms-backend ^13.4 || 13.*.*@dev || 14.*.*@dev || 14.*.* -> satisfiable by typo3/cms-backend[v13.0.0, ..., 13.4.x-dev, 14.0.x-dev (alias of dev-main)]. - typo3/cms-backend v13.0.0 requires typo3/cms-core 13.0.0 -> found typo3/cms-core[v13.0.0] but it conflicts with your root composer.json require (^12). - typo3/cms-backend v13.0.1 requires typo3/cms-core 13.0.1 -> found typo3/cms-core[v13.0.1] but it conflicts with your root composer.json require (^12). - typo3/cms-backend 13.0.x-dev requires typo3/cms-core 13.0.*@dev -> found typo3/cms-core[v13.0.0, v13.0.1, 13.0.x-dev] but it conflicts with your root composer.json require (^12). - typo3/cms-backend v13.1.0 requires typo3/cms-core 13.1.0 -> found typo3/cms-core[v13.1.0] but it conflicts with your root composer.json require (^12). - typo3/cms-backend v13.1.1 requires typo3/cms-core 13.1.1 -> found typo3/cms-core[v13.1.1] but it conflicts with your root composer.json require (^12). - typo3/cms-backend 13.1.x-dev requires typo3/cms-core 13.1.*@dev -> found typo3/cms-core[v13.1.0, v13.1.1, 13.1.x-dev] but it conflicts with your root composer.json require (^12). - typo3/cms-backend v13.2.1 requires typo3/cms-core 13.2.1 -> found typo3/cms-core[v13.2.1] but it conflicts with your root composer.json require (^12). - typo3/cms-backend v13.3.0 requires typo3/cms-core 13.3.0 -> found typo3/cms-core[v13.3.0] but it conflicts with your root composer.json require (^12). - typo3/cms-backend v13.3.1 requires typo3/cms-core 13.3.1 -> found typo3/cms-core[v13.3.1] but it conflicts with your root composer.json require (^12). - typo3/cms-backend 13.3.x-dev requires typo3/cms-core 13.3.*@dev -> found typo3/cms-core[v13.3.0, v13.3.1, 13.3.x-dev] but it conflicts with your root composer.json require (^12). - typo3/cms-backend v13.4.0 requires typo3/cms-core 13.4.0 -> found typo3/cms-core[v13.4.0] but it conflicts with your root composer.json require (^12). - typo3/cms-backend 13.4.x-dev requires typo3/cms-core 13.4.*@dev -> found typo3/cms-core[v13.4.0, 13.4.x-dev] but it conflicts with your root composer.json require (^12). - typo3/cms-backend dev-main requires typo3/cms-core 14.0.*@dev -> found typo3/cms-core[dev-main, 14.0.x-dev (alias of dev-main)] but it conflicts with your root composer.json require (^12). - typo3/cms-backend 14.0.x-dev is an alias of typo3/cms-backend dev-main and thus requires it to be installed too.