This configuration tab contains settings for how the checkout normally should work. Here, you can choose to use the default order id reference or if you want to go with WooCommerce incremental post-id's as order numbers. At the bottom of the page you also have a list of which payment methods you have available for the moment. This can be updated manually on this page, but will usually update when you enter or change credentials on the first page.
Outdated callback URLs
One problem that can be very common is when we are testing our platform before deploying it to production. If your site have två different urls, the admin interface has the opportunity to warn you (globally in admin) when the callbacks starts to differ with the expected URL's. The part of the plugin uses a similarity comparison to decide whether the plugin urls are desynched or not. The URLs has to be more less than 90% similar to the currently registered callback (discovered at Resurs Bank, not the plugin) to before you get this kind of pop up (which is delayed for five seconds after the page load).
Clicking "Cancel" will abort this update and the popup will come back on next reload, until the problem is fixed. This is written to avoid that orders are not handled in the storefront properly. If you choose to click "OK", which is similar to "Yes", you will after the synchronization be informed with an alert, unless you're on the same page as the callbacks. In that case, the page will instead reload.
The next configuration page is much smaller. You usually don't have to care about this at all and all settings works best disabled. This setup decides how fraud control should work and normally "all disabled" also means asynchronous flow. Those settings enabled only works in simplified and hosted flow. Then why are they present? Well, if you work with for example tickets and travels, you may want to make sure that people really can pay for them. By enabling the fraud control you also enter synchronous mode, meaning you can instantly annul all payments that are denied by Resurs Bank. And if the payments are booked and successful, you can make Resurs Bank finalize the payments instantly.