For an 3D secure payment(creditcard) on Adyen (payment provider) you first do a Authorization call to authorize the card. If the card is enrolled for 3D secure the shopper is redirected to the bank page where he can authentication himself. After authentication the shopper comes back to the shop and a second API call needs to be done to validate the 3D secure payment. The nicest way to do this is using the executeCommand through DI in the same way as authorized,refund,cancel and capture. In the Magento\Payment\Model\Method\Adapter file there is no 3D secure command. Could you add this or could you make executeCommand protected instead of private so you can overwrite this in a custom Adapter for your payment method ?