If you look at the code in gateways/paypal.php, that’s an example showing a custom payment gateway. It contains everything you might need; although the specific requirements for any given gateway are quite different.
All gateways have some unique needs, but the fundamentals for adding a gateway to the set of available gateways, creating settings for that gateway, and the core functions that need to be executed are shown in that file.
Okay thanks.
Where can i change the look of the gateway choose? at the payment page for our users?
And what if i have a second plugin from the gateway it self. Would it somehow be possible to insert?
You can redesign anything using custom CSS, which can be added in many different ways.
If you have an existing plugin from the payment gateway you can probably adapt it’s code into a gateway for My Tickets, but you wouldn’t be able to just use it for My Tickets directly.