Sheet as Webservice Api

google-sheet-update.js

const sheet = SpreadsheetApp.getActive().getSheetByName('Sheet1')

function doGet(e){
  const action = e.parameter.action;
  
  //URL_SCRIPT/exec?action=getItems
  if(action == 'getItems'){
    return getItems(e);
  }
}

function getItems(e){
  let records={};
  const rows = sheet.getRange(2, 1, sheet.getLastRow() - 1,sheet.getLastColumn()).getValues();
  const sizeRows = rows.length; 
  let data = [];

  for (let i = 0; i < sizeRows; i++) {
    let row = rows[i],
    record  = {};
    record['Title'] = row[0];
    record['Description']=row[1];
    record['Price']=row[2];
    data.push(record);
   }
  records.items = data;
  let result=JSON.stringify(records);
  return ContentService.createTextOutput(result).setMimeType(ContentService.MimeType.JSON);
}

google-sheets-api.js

//If appscript created from main page,
// this way u can refer to other sheet by the url
var ss = SpreadsheetApp.openByUrl("https://docs.google.com/spreadsheets/d/1q8tX6qEj5NbWKaGX3hWAzoSbrHqwM9IN-8bqOZmbIIo/edit#gid=0"); // sheet of account 

var sheet = ss.getSheetByName("Sheet1"); //it is the sheet name .. so it should match 
function doGet(e){
  var action = e.parameter.action;
  
  //URL_SCRIPT/exec?action=getItems
  if(action == 'getItems'){
    return getItems(e);
  }
}

function getItems(e){
  var records={};
  var rows = sheet.getRange(2, 1, sheet.getLastRow() - 1,sheet.getLastColumn()).getValues();
      data = [];

  for (var r = 0, l = rows.length; r < l; r++) {
    var row     = rows[r],
        record  = {};
    record['Title'] = row[0];
    record['Description']=row[1];
    record['Price']=row[2];
    data.push(record);
   }
  records.items = data;
  var result=JSON.stringify(records);
  return ContentService.createTextOutput(result).setMimeType(ContentService.MimeType.JSON);
}

const sheet = SpreadsheetApp.getActive().getSheetByName('Sheet1')