wkhtmltopdf options : How to handle Non-English file name across different OS systems

I’m encountering issues with wkhtmltopdf when passing non-English file names as arguments. For example passing the file named Japan日本.xml, the output file is saved as Japan.xml missing non-english characters instead of Japan日本.xml. This problem occurs on my Ubuntu server, while my client PC runs Windows. I’ve ensured that the necessary fonts are installed on the server, and the locale settings are configured to support UTF-8. However, the issue persists.
I also found similar issue reported in wkhtmltopdf-Repository.

PHP Code Snippet:

<?php
$WKHTMLTOPDF = $wkhtmltopdf_path;
$_options = [
    '--dump-outline ' . escapeshellarg('/usr/local/apache2/htdocs/Japan日本.xml'),
    $input_file_path,
    $output_file_path
];

$options_string = implode(' ', $_options);
$output = shell_exec('"' . $WKHTMLTOPDF . '" ' . $options_string);
?>

Also, if you notice how I pass the option parameters, sometimes we forget to add a space between the command option and its value, which causes issues. It would be helpful if you could explain how to keep proper spacing between command options.