There can be instances where you come across issues regarding the encoding formats of Chinese characters in shipping documents using the plugin WooCommerce PDF Invoice, Packing Slip, Delivery Notes and Shipping Label. You can just follow the steps explained below to get it fixed.
Step 1: Download the file, and extract the zip. Then host the file fireflysung.ttf somewhere on your site.
Step 2: Copy below code to your active invoice template code editor and replace the URL (http://<site_name>/wp-content/fireflysung.ttf) format(“truetype”) with the URL of the file hosted on your site.
font-family: "Firefly Sung";
src: url(http://<site_name>/wp-content/fireflysung.ttf) format("truetype");
font-family: Firefly Sung, DejaVu Sans, sans-serif; font-weight:400 !important;