error Deprecated

hello i have this problem in php 8.2

Deprecated: Creation of dynamic property DUPX_ArchiveConfig::$dup_type is deprecated in D:\xampp\htdocs\fmps\dup-installer\classes\config\class.archive.config.php on line 118

protected function __construct()

    {

        $config_filepath = DUPX_Package::getPackageArchivePath();

        if (!file_exists($config_filepath)) {

            throw new Exception("Archive file $config_filepath doesn't exist");

        }

        if (($file_contents = file_get_contents($config_filepath)) === false) {

            throw new Exception("Can\'t read Archive file $config_filepath");

        }

        if (($data = json_decode($file_contents)) === null) {

            throw new Exception("Can\'t decode archive json");

        }

        foreach ($data as $key => $value) {

  line 118 --->          $this->{$key} = $value;

        }

        //Instance Updates:

        $this->blogNameSafe = preg_replace("/[^A-Za-z0-9?!]/", '', $this->blogname);

    }