Add Delivery Fee to Checkout

I run a custom-coded e-commerce site built with Laravel on the back-end and JavaScript on the front-end. Right now the checkout total ignores delivery charges, and I need that fixed as soon as possible.

Here’s what I need from you:
• Inject a delivery-charge field into the existing checkout flow (server and front-end).
• Make sure the amount is included in the order summary, payment gateway payload, confirmation email, and admin dashboard.
• Keep the solution clean, commented, and fully compatible with my current Laravel version and JavaScript framework.
• Prove it works with a quick demo or screenshots of a test order showing the new total.

Code access can be provided via Hostinger Sharing Account, whichever is easiest for you. Turnaround is ASAP, so if you know your way around Laravel routing, controllers, Blade templates (or Vue/React if necessary), this should be a straightforward task.