Hello @remymedranda
I’m sorry i missed your support question!
As you can understand it is impossible for us to support all third-party attributes plugins, so that is why the “third party attributes” option has been added. It should support any third party plugin, but you need to know the meta_key under which the attributes are stored in the database.
To find the correct (meta)key:
1. Create on new product and add a value in the “gtin” custom field.
2. Check your database and go to table wp_postmeta (with phpmysql for example)
3. sort the table on meta_id Descending
4. The top meta_key would be the meta_key from your custom product field.
If you have found the meta_key, you can make a filter string like %meta_key% (only the prefix of the key) that should be added to the “third party attributes” field you find in our plugin settings page. After that, you should have to search for how it is displayed in the source list as that can vary for each plugin as well.
We do have our own little helper plugin to add GTIN and other helpfull fields to woocommerce that will show up in the source dropdown of our plugin.
https://github.com/Auke1810/woocommerce-additional-product-identifiers