1. Login to Online Check Writer and select Apps.
2. Click Bill.com and click on the Connect button.
3. Sign in to your Bill.com account using the credentials and click on Connect.
4. Once you have done, you can see your company on the page.

To import bills from Bill.com, 

1. Go to Bill / To Pay from the side panel.
2. Click on Import Bills and select Bill.com from the tabs.
3. Choose the company and update Import Settings: select Time Span and Download Filter.
4. Click Start Importing.