Page options

i have adding this in my function.php

function custom_bewpi_mpdf_options( $options ) {
    $options['mode'] = '';
    $options['format'] = 'A5';
    $options['default_font_size'] = 0;
    $options['default_font'] = 'opensans';
    $options['margin_left'] = 14;
    $options['margin_right'] = 14;
    $options['margin_top'] = 14;
    $options['margin_bottom'] = 0;
    $options['margin_header'] = 14;
    $options['margin_footer'] = 6;
    $options['orientation'] = 'P';
    return $options;
 }

But i still don′t get the params ‘orientation’.
What are the option available?

i just want a invoice with landscape orientation and i already tried the change $options[‘orientation’] = ‘P’; to $options[‘orientation’] = ‘L’; but this doesn′t work

https://www.ads-software.com/plugins/woocommerce-pdf-invoices/