Zakeke automatically gets the variants from your store catalog and this is the only way to have the variants properly created inside Zakeke. It means that you first need to set the variants of your product in your store, knowing that, if changes are applied to those variants (example: variant's names), Zakeke won't be able to recognize and match the variants created inside your store.

In order to solve the issue you need to:

1. Go inside Zakeke's Customizable products section
2. Select the product
3. Click on Go to Variations
4. Edit the product variants and reassign them correctly by clicking the edit icon
5. Once edits are done, click on Go to review and save the settings

Please see also these guidelines on creating and managing product variants inside Zakeke:

• Variants
• How to make a price for each product variant
• How to associate a pre-designed template with a single variant
• Why I'm not able to set product variations?
• Editing the attributes/variants of the product in your store after a product has been published as a customizable product