Set values saperated by a vertical pipe | (e.g., S | M | L | XL or 36 | 37 | 38 | 39 | 40).
Make sure that the Used for variations is checked ✅.
Save the attributes, click Save attributes.
Create Variations
Select Create variations from all attributes to have WooCommerce create every possible combination of variations from your attributes and their values and select Go.
Optionally, set defaults for variations and manage stock at the variation level in the Inventory tab.
Adding Variation Data
Each variation can have the following properties. Enter the product data into the fields.
Add variation image (recommended) and image gallery (optional). Variation image makes it easier for customers to identify the product they have selected.
Check/tick Enabled to enable this variation to show in your e-commerce store.
Enter product regular price (required) and sale price (optional). You can schedule sale for certain duration according to your needs.