Запись в файл

Синхронно

const fs = require('fs');
fs.writeFileSync("foo.txt", "bar");

Асинхронно

const fs = require('fs').promises;
await fs.writeFile('/path/to/file.txt', 'data to write');

Warning: Undefined array key 1 in /var/www/html/dev.familion.ru/wp-content/plugins/echo-knowledge-base/includes/features/articles/class-epkb-articles-setup.php on line 699