https://www.pbainbridge.co.uk/2019/08/clear-cell-content-on-google-sheet-edit.html

Clear cell content on Google Sheet edit.gs

/*
This Function is designed to clear the adjacent cell to the right of the one
that has just been edited - so long as it is within the column we specify 
(so only edits in column 2 here).
*/

function onEdit(e) {
  
  // get edited cell from the event object
  var cell = e.range;
  
  // get edited cell column from the event object
  var column = cell.getColumn();
  Logger.log('Column is: ' + column);
  
  // get edited cell row from the event object
  var row = cell.getRow();
  Logger.log('Row is: ' + row);
  
  // get spreadsheet from the event object
  var source = e.source;
  
  if (column == 2) {
    // clear adjacent cell value
    var ss = source.getSheetByName('Clear cell');
    ss.getRange(row, column+1).clear();
  }
  else {}
  
}