You can add or edit your bank account information on the Get Funded! section of your campaign Edit mode.  To get there: 

• Log in to Indiegogo
• Go to your campaign page
• Click Manage Campaign
• Click Edit
• Click on the 4th tab, Get Funded!
• Enter your bank account details (about half-way down the page). 

Please note that you will not be prompted to enter any bank account information until after you have begun raising funds.