Gutenberg support was adding in version 2.0. Are you using the latest version?
Here’s a screenshot from today, so this is how it should look:
https://cl.ly/8508f7fadac8
If you aren’t seeing this, there could be a conflict with either your theme or another plugin. Here’s how I usually isolate a potential conflict:
- Temporarily switch back to a default WordPress theme (or Storefront). If this resolves the issue, then please bring this to the attention of your theme author.
- If the issue persists, then disable all other plugins except for WooCommerce and the extension. If this fixes the issue, then slowly re-enable plugins until you find the one causing it.
To avoid causing any problems to your live site, the best way to do this would be to try setting up a staging site, for example using a plugin such as WP Staging and then troubleshoot the issue on the staging site.