Here is a list of supported Liquid fields in Techship MH10 Labels -
shipment.lines
order.ship_to_name
order.ship_to_company
carrier_settings.sender_company
carrier_settings.sender_address1
carrier_settings.sender_address2
carrier_settings.city
carrier_settings.state
carrier_settings.zip
shipto | zpl_escape
order.addresses
order.city
order.state
order.zip
order.additional_wms_data.WmsBillOfLading
order.additional_wms_data.DCNumber
shipment.customer_sku
order.customer_po
order.customer_order
shipment.warehouse_sku
line.description
order.additional_wms_data.CUSTOM_WmsUpc
shipment.sscc
Accessing PO in store for References:
mapper_order_references.qualifier