Installation failed

[jmlechiguero]

Hello, first thing. Thanks for continuing the project.
Tell them that when performing the installation with the steps indicated in the README file, the install.php file does not exist.
when starting the installation with the index.php, from the same folder, this error appears:

Fatal error: During inheritance of ArrayAccess: Uncaught ErrorException: Return type of Language::offsetExists($offset) should either be compatible with ArrayAccess::offsetExists(mixed $offset): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in ...nova\includes\classes\Language.class.php:185 Stack trace: #0 ...nova\includes\classes\Language.class.php(18): errorHandler(8192, 'Return type of ...', 'C:\Utiles\Xampp...', 185) #1 ...nova\includes\common.php(57): require('C:\Utiles\Xampp...') #2 ...nova\install\index.php(23): require('C:\Utiles\Xampp...') #3 {main} in ...nova\includes\classes\Language.class.php on line 18