script needed to find the last row and execute a copy function down

Jeff_Hunt 

That could be

function main(workbook: ExcelScript.Workbook) {
    
    const sheet = workbook
        .getWorksheet("Sheet1")

    const lastRowAddress = sheet
        .getUsedRange()
        .getLastCell()
        .getAddress()

    const lastRow = sheet
        .getRange(lastRowAddress)
        .getEntireRow()
        .getUsedRange()

        lastRow
        .getOffsetRange(1,0)
        .copyFrom(lastRow)

}