View file phpBB3/config/installer/container/services_install_requirements.yml

services:
    installer.requirements.check_filesystem:
        class: phpbb\install\module\requirements\task\check_filesystem
        arguments:
            - '@filesystem'
            - '@installer.helper.iohandler'
            - '%core.root_path%'
            - '%core.php_ext%'
        tags:
            - { name: installer_requirements, order: 10 }

    installer.requirements.check_server_environment:
        class: phpbb\install\module\requirements\task\check_server_environment
        arguments:
            - '@installer.helper.database'
            - '@installer.helper.iohandler'
        tags:
            - { name: installer_requirements, order: 20 }
            - { name: update_requirements, order: 20 }

    installer.module.install_requirements_collection:
        class: phpbb\di\ordered_service_collection
        arguments:
            - '@service_container'
        tags:
            - { name: service_collection, tag: installer_requirements, class_name_aware: true }

# Please note, that the name of this module is hard coded in the installer service
    installer.module.requirements_install:
        class: phpbb\install\module\requirements\install_module
        parent: installer.module_base
        arguments:
            - '@installer.module.install_requirements_collection'
            - true
            - false
        tags:
            - { name: installer_install_module, order: 10 }