If you have a US bank account you can add it to your Swan account. To do so, navigate to the main menu in the upper right of your screen. Click on the small circle icon. Then in the following drop-down menu select "Payment methods" as shown below.
That will bring you to a new screen showing your existing bank accounts added. Please select "Add another bank account" as shown below.
If you are not a US resident, you can only add a bank account to your account if you have a US bank account. If that is the case, please write to support to enable this feature, once this feature is enabled for you can follow the directions above.