const ss2 = SpreadsheetApp.openByUrl("https://docs.google.com/spreadsheets/d/ID2/edit");
  const Sh2 = ss2.getSheetByName("SheetName");
 
  var rowNum = Sh2.getRange("L4").getValue();

  // DB2에서 해당 행을 읽어들임

  const ss1 = SpreadsheetApp.openByUrl("https://docs.google.com/spreadsheets/d/ID1/edit");
  const Sh1 = ss1.getSheetByName("DB2");
 
  var Sh1Col = Sh1.getMaxColumns();
  var valuesToCopy = Sh1.getRange(rowNum, 1, 1, Sh1Col).getValues();

  Sh2.getRange(1,1,1,Sh1Col).setValues(valuesToCopy);

 

https://stackoverflow.com/questions/50815817/google-script-select-an-entire-row-in-a-google-spreadsheet