In the latest version of excalibur you as a developer can choose which kind of checkout you want to offer. The normal checkout process you already know is untouched except of the enhanced design. You can continue using this route, especially when you want to offer individualized checkout - processes.
If you dont want to think about checking out your customer, we recommend using the express checkout. Therefore we have created the new routes you will access if you click on the express - checkout button appearing in the cart section. If you have only want to offer the express checkout, just hide the other button:
In the next step the user will see a shortened checkout process where many steps are put together. Payment - methods are delivered by mollie by default but in the file express.html (twig template) you have a section where you can also display desired payment - methods. This section is commented out by default.
After this step the user will be redirected to the order-summary page.
Here you find git repo for excalibur : https://github.com/sleekshop/excalibur