How to do the Import AutoInvoice process in AR with multiple lines in a single invoice?

Summary:

After importing the Autoinvoice, an error appears as shown below:
"Each line must have a unique combination of INTERFACE_LINE_ATTRIBUTE1-15 and INTERFACE_LINE_CONTEXT values for the line transaction flexfield."
I have created a context for "OPERA INVOICE" and the LINE_ATTRIBUTE1 as the Invoice Number and the LINE_ATTRIBUTE2 as the line number in the line transaction Descriptive Flexfields.
A line ordering rule has been created and also a group ordering rule has been already created accordingly but still the error appears.

Is there any configurations to follow to enable to import multiple lines in a single invoice through the "Import AutoInvoice" process?