Magento 2 – Cannot Run Commands in Terminal

When try run command in terminal example
php bin setup:upgrade
show like these error messages. Not only that but also all commands

-[ReflectionException]
Class Magento\Config\Console\Command\ConfigSet\ProcessorFacadeFactory does
not exist.
– [ReflectionException]
Class Magento\Config\Console\Command\ConfigSet\ProcessorFacadeFactory does
not exist.
– [RuntimeException]
Can't create directory /var/www/html/robolk/generated/code/Magento/Config/Console/Command/ConfigSet/.
in [Magento\Config\Console\Command\ConfigSet\ProcessorFacadeFactory].

Why is Magento showing these errors?