Set up e-commerce checkout

I need to launch checkout that actually converts. Install and configure the e-commerce plugin on our site, add our product catalog of 12 digital and physical SKUs with images and descriptions, set the currency to US dollars, enable secure payments via the Stripe account owned by finance, require buyer email and shipping address only when a physical item is purchased, and run a test purchase through to the Stripe dashboard by Friday so we can start taking orders Monday.

Before I send this live to marketing, make the checkout easy to finish: surface total cost and tax before the payment step, collapse optional account creation into a single checkbox, show shipping cost early for physical SKUs, ensure guest checkout works, and flag any product or gateway settings that will cause payment failures or abandoned carts.

I just connected our Stripe account and uploaded 12 products, then a test card payment returned a gateway error. The customer is marketing who expects sales next week; finance says the account is verified. I’m worried it’s a webhook or mode mismatch I can’t see. What is the most likely cause and the exact next steps to get a successful test charge before Friday?

We keep losing launch days to checkout failures: wrong gateway mode, missing webhook endpoints, inconsistent SKU settings, and nobody owns the end-to-end payment test. How should we change our prelaunch routine so payments are validated earlier and reliably? Recommend a short checklist and one habit to enforce at least two days before any launch.