I now use https://apps.shopify.com/partners/wizard-labs.  

I just downloaded Invoice Wizard app which has both HSN Code + Country of Origin fields.

For anyone struggling with invoice print including HS code, I managed to include this code<table class="table-tabular" style="margin: 0 0 1.5em 0;"><thead><tr><th>Quantity</th><th>Item</th><th>HSN Code</th>{% if show_line_item_taxes %}<th>Taxes</th>{...

@NessaSnipe Do you mind please sharing how to add this {{ line_item.variant.metafields.harmonized_system_code.value }} (which line to use in the printer app) as it does not show up.Many thanks