Everything on this site works locally in your browser. To sync changes across devices (phone, office, laptop), the Apps Script web app behind the Sync button must implement these actions. Each is a simple GET with the parameters shown.

Minimum Apps Script skeleton:

function doGet(e){
  const p = e.parameter;
  const ss = SpreadsheetApp.getActive();
  switch(p.action){
    case 'reorderImages':      return reorder_(ss,'Images',p.order);
    case 'reorderServices':    return reorder_(ss,'Services',p.order);
    case 'reorderBeforeAfter': return reorder_(ss,'BeforeAfter',p.order);
    case 'updateImage':        return updateRow_(ss,'Images',p);
    case 'updateVideo':        return updateRow_(ss,'Videos',p);
    case 'updateBeforeAfter':  return updateRow_(ss,'BeforeAfter',p);
    case 'updateService':      return updateRow_(ss,'Services',p);
    case 'trackEvent':         return track_(ss,p);
  }
  return ContentService.createTextOutput(JSON.stringify({ok:true}))
    .setMimeType(ContentService.MimeType.JSON);
}