To proceed, please ensure you have purchased the Add-On for syncing Items Custom Fields and have installed the ACF plugin (free).
With this addon, you can sync the custom fields of Simple Items and Grouped Items to WooCommerce.
All you need to do is make sure the ACF Custom Fields names match the Custom Fields API Names in Zoho Inventory. Once you have done that, you can simply click on the Sync button of the type of items you want synced. This is how it should look like in Zoho and in WooCommerce: