We can map the WooCommerce SKU field or any meta field to the Barcode field in EposNow.
A popular plugin that our clients use to set barcodes and auto generate barcodes in WooCommerce is the EAN for WooCommerce plugin. This plugin can auto generate barcodes, make sure they are unique and also validate them. Our integration supports this plugin and will be compatible with any plugin that stores the barcode in the product meta data.
If you are not sure about compatibility, then just get in touch with support and we can check for you.