To create variants for an existing product, please make sure that you haven’t created any invoices with that product, because variants cannot be added for a product which has transactions.
If the product doesn’t have any transactions, please follow the steps mentioned in the article below.
Step 1: Go to “Products & Services” section and then click on “Edit item” for the product you would like to add variants for.
Step 2: Click on “+ Variants”
Step 3: Once the variants are edited, click on “Update Item.”
