post
https://api.ecartapi.com/api/v2/products//variants
Use this resource to create a simple variant of a previously created product. The option values are not random; it's an example of aspectId:"200" with its valid value:"2", for a product created with categoryId/taxonomyId:"1".
Please review our Etsy documentation for more information on aspects and categories.
To create multiple variants with different options, we recommend using the bulk create/update product variant resource.
Note: options, sku, price, pickupOptionId, and status.active are required.