Activating Accounts payable

I have enabled Suppliers & Suppliers Invoices. Then entered first Supplier & then their sales invoice. Accounts payable is listed under Liabilities on the Balance Sheet but does not appear on the account drop down box in Suppliers Invoices. Please help. Peter

This is not how Manager works. It automatically allocate the liability to accounts payable. What you should assign is the corresponding account in double entry accounting… ie a revenue or an asset.

Thank you