How to convert the column sum-function-total to dollars in Oracle SQL? I am unable to format the below query intending to display the column-alias total re-formatted to display as dollars.  Though unsuccessful, I suspect a nested solution combined with TO_CHAR, is appropriate but I haven't succeeded with my attempts.

SELECT SUM(TO_CHAR(invoice_total,'$999,999.99')) AS "Total Invoice Amount"
FROM company.invoices;


Can anyone please assist?  Thank you.
This was a simple-syntax issue, which I unable to see due to my growing frustration-thank you.

SELECT TO_CHAR(sum(invoice_total),'$999,999.99') AS "Total Invoice Amount"
FROM company.invoices;