If you are using Quickbooks Online, you can indirectly sync your bills and invoices from your CRM with Truss.
Here's how it works:
Setup integration from Truss to QBO, see detailed instructions here
Setup integration from QBO to CRM, e.g. Buildertrend, Jobtread
When you create invoices/bills in your CRM these sync into Quickbooks Online (QBO)
QBO then syncs bills & invoices into Truss
Payment is sent and completed in Truss
Once payment is complete, Truss syncs back to QBO and marks the transaction as 'paid'
QBO finally syncs the completed invoice/bill back to CRM