How Do I Copy the header row of the source sheet to new sheets using google app script/Javascript

[Levi]

I have a java script/Google Script code that creates new sheets/tabs based on the values in the first column. Say if John appears 5 times in the sheet, it creates a new sheet with the name "John" and pastes all row values that have John in the first Column. If the sheets already exist it logs "sheet exists" and exists.  I now have a challenge of ensuring that while the rows are copied to a new sheet, it also copies the title row(first row). I also wanted to add a condition that, If the sheet already exists, It overwrites the contents or the sheet. Been trying different codes for two days but and really getting headway.  

I will appreciate any help here.

Here is the main sheet.

You will notice when data is copied to a new sheet, the first row is neglected.

And this is my source code.

function newSheet() {

    var ss = SpreadsheetApp.getActiveSpreadsheet();

    var templateSheet = ss.getActiveSheet();

    var sheet1 = ss.getSheetByName("main")

    var getNames = [...new Set(sheet1.getRange("A2:A").getValues().filter(String).toString().split(","))];

    for (var i = 0; i < getNames.length; i++) {

        var copy = ss.getSheetByName(getNames[i]);

        if (copy) { 

            Logger.log("Sheet already exists");  // I would like this to overwrite existing sheet

        } else {

            //The copyTo function will copy the entire sheet

            //templateSheet.copyTo(ss).setName(getNames[i]);

            var rowIndexes = sheet1.getRange("A:A").getValues()

                .map((value, index) => [value[0], (index + 1)])

                .filter(value => value[0] === getNames[i]);

            var namedSheet = ss.insertSheet(getNames[i]);

            rowIndexes.map(index => {

                var rowValues = sheet1.getRange(index[1], 1, 1, sheet1.getLastColumn()).getValues();

                namedSheet.appendRow(rowValues[0]);

            });

            //Logger.log(rowValues);

          

            ss.setActiveSheet(ss.getSheetByName(getNames[i]));

            ss.moveActiveSheet(ss.getNumSheets());

        }

    }

}

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