Once you have logged in to your account online, click on the menu icon in the upper left-hand corner. Select Partner Earnings. Here you will see 3 tabs at the top of the page: Payment Statements, Tax Information, Banking. You will automatically be on the Payment Statements tab. Click the Banking tab just to the right.
Once you click the Banking tab, you may have to enter your log in information as a security measure. Enter your information. You will then be able to see the banking information you have on file. If you want to change your information, or add your bank account for the first time, click the Edit button and enter the pertinent information for your bank and taxes.