[TYPO3-english] How to hook TYPO3 Form submit

[Mikel]

There is missing the extension declaration file ext_emconf —> https://docs.typo3.org/typo3cms/CoreApiReference/ExtensionArchitecture/DeclarationFile/Index.html <https://docs.typo3.org/typo3cms/CoreApiReference/ExtensionArchitecture/DeclarationFile/Index.html>
Example content:
$EM_CONF[$_EXTKEY] = [
    'title' => ‚Your ext title',
    'description' => '',
    'category' => 'templates',
    'author' => ‚Your name',
    'author_email' => ‚your mail',
    'state' => 'alpha',
    'internal' => '',
    'uploadfolder' => '0',
    'createDirs' => '',
    'clearCacheOnLoad' => 0,
    'version' => '0.0.1',
    'constraints' => [
        'depends' => [
            'typo3' => '8.7.0-8.7.99',
        ],
        'conflicts' => [],
        'suggests' => [],
    ],
];