How to add flat rate shipping fee to order total

You can use the CURRENCY function with a number value to set a fixed shipping fee. Add a short answer question in Google Forms and write the formula using CURRENCY function in Formfacade.

Calculating shipping charges

Custom rates based on subtotal or weight – Ecwid Help Center

How to Add Flat rate Shipping on Shopify

OpenCart - Total Based Shipping with Multi Flat Rate

When to use flat-rate shipping (and when to avoid it)

Based on Order Total – Pixpa Help

Flat Rate Shipping Explained

How To Increase Sales With Flat-Rate Shipping

OpenCart - Total Based Shipping with Multi Flat Rate

Calculate Shipping Rates for Pickup and Non Pickup Products

Create a shipping rate by percentage

How To Increase Sales With Flat-Rate Shipping