Add the product of the page to the cart with its Add to cart button, and wait until the cart count goes up or the add to cart error appears. On a real store this changes the store's data: use a store in test mode.
Examples
When I add the product to the cart
When we add the product to the cart
And I add the product to the cart
And we add the product to the cart
Then I add the product to the cart
Pattern
When(/^(I |we )*add the product to the cart$/, …)
Part of @webship-js/webflow-steps (github.com/webship/webflow-steps), a step pack for Webship-js 2.0.x.