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function addCheckbox() {
var sheet = SpreadsheetApp.getActiveSpreadsheet().getActiveSheet();
var cell = sheet.getRange("A1"); // Replace "A1" with the desired cell reference
// Insert checkbox
var checkbox = sheet.getRange(cell.getRow(), cell.getColumn()).insertCheckboxes();
// Set checkbox value
checkbox.setChecked(true); // Change to false to set it as unchecked
}