We're sorry. This feature is not included in your QuickBooks Online Simple Start subscription.
QuickBooks Online Simple Start subscription does not support syncing with some apps, such as Bill.com.
To be able to sync with Bill.com, please upgrade to QuickBooks Online Essentials or Plus. Please see the QuickBooks Online Feature Comparison Chart to determine the subscription you will need to sync with Bill.com, based on the features you would like to use.