In order to assign single design templates for all configurable products at once, you need to assign the design template to the parent product. Once you’ve assigned it to the parent product, all the related child products will be assigned with the same template by default.
- Navigate to the Catalogs > Products.
- Select the parent product which you must have created as a configurable product.
- Open it, and on the Product information page, navigate to the “Product Designer” section.
- In the Pre-loaded template field, select the template that you want to assign to all your products. And click save. Hence, all your products will have that template as a pre-loaded template. You can check the same by going to your front-end store and personalizing the configurable product.