Magento 2.3.x CE Payment Gateway Interface Redirects to External PSP Window/Endpoint
Hi All, I'm a newbie in Magento, currently trying to customise/create new payment gateway interface for a CE version 2.3.x setup. I've tried referring to the devdocs, used the famous Sample module project as a guide, and also checked multiple forums, but no dice. Sometimes I got myself confused the more I checked. I wonder if I'm missing something.
Basically in my case, the gateway's interface is simple, upon placeOrder, that button should POST relevant data to a URL (a payment window by the Payment Service Provider or "PSP"). Consumers will pay using that window, and upon success (or failure), that PSP window will redirect back to a page of our choice, with the success/failure status.
From the sample files, the eventual button will call the placeOrder command. I believe that is for the "Authorise" action. Doing some research, I understand that the action to use should be "Authorise and Capture" for my case, as opposed to "Authorise" only.
So, from here, where do we customise/overload/override this command so that it can redirect to that desired PSP's payment window?