google apps script for logging to spreadsheet

apps.js

function doPost(e) {
  var sheet = SpreadsheetApp.getActiveSpreadsheet().getActiveSheet();
  var mood = e.parameter.mood;
  var who = e.parameter.who;
  var notes = e.parameter.notes;
  var date = new Date();
  
  if (who == null || mood == null) {
    return ContentService.createTextOutput("missing param").setMimeType(ContentService.MimeType.TEXT);
  }
  sheet.appendRow([date, who, mood, notes]);
  
  return ContentService.createTextOutput("success").setMimeType(ContentService.MimeType.TEXT);
}