Commas thousand separator to a float number

Question

I have a software which reads excels fields in nodejs, captures the value and parse it to float, i want to print the result of the float number, Example: 1200.00 -> 1,200.00, any idea?

parseFloat(excelFileSheets.Hoja1[i]["TOTAL DE ING."]).toFixed(2);

I just tried

parseFloat(excelFileSheets.Hoja1[i]["TOTAL DE ING."]).toFixed(2).toLocaleString("DE-de");