Cancel parameters route and filename index.php
Make URLs more beautiful
before http://www.demo.com/index.php?route=account/register
now http://www.demo.com/account-register
Attention
If you don not edit SEO URL
url will change rule is index.php?route=checkout/cart -> checkout-cart
Else you edit SEO URL like the following figure

url will change rule is index.php?route=checkout/cart -> shippingcart

download url https://www.opencart.com/index.php?route=marketplace/extension/info&extension_id=36334