This is because your Laravel version is not compatible with the Doctrine DBAL version you are using.

1. Check your version : composer why carbonphp/carbon-doctrine-types

2. Downgrade your version : composer require nesbot/carbon:^2.66(whatever your version is)

3. Remove your dependencies : composer remove carbonphp/carbon-doctrine-types

4. Install the compatible ones : composer require doctrine/dbal:^3.0(whatever your version is)