Open your Google Sheet → Extensions → Apps Script
Delete existing code and paste this:
function doGet() {
const ss = SpreadsheetApp.getActiveSpreadsheet();
const result = {};
['Campaigns','Lead tracker','Traction Data','LinkedIn','Snapshot']
.forEach(n=>{try{const s=ss.getSheetByName(n);if(s)result[n]=s.getDataRange().getValues();}catch(e){}});
return ContentService.createTextOutput(JSON.stringify(result)).setMimeType(ContentService.MimeType.JSON);
}