Register with tripadvisor at : http://www.tripadvisor.com/APIAccessSupport
once your account approved they will send you email as below :
You have been granted provisional access to our API in order to begin development, but please note that permission is required before TripAdvisor data can be displayed on any publicly-accessible webpage or app.
Your API development key is a814718bc3e347d9ac93c4ca5a7a39d3
This key entitles you to 1,000 API calls a day.
Copy your API development key and follow simple steps
01. login to your admin panel
02. from general menu click on integrations
03. from integration''s click on settings for tripadvisor
04. paste your API development key and click and submit
05. when you add any hotel you will find tripadvisor textbox to add the reviews ID
06. to get the ID of any hotel from tripadvisor goto : tripadvisor.com and search that hotel
07. on the reviews page you have to copy the ID from url which is numeric 299065. once you copied go back to your admin hotel adding page and paste the ID in tripadvisors textbox and submit.
08. now goto your hotel page and you will see the tripadvisor widget with reviews result
When your integration is complete, please send an email to firstname.lastname@example.org with a link and any necessary login information to test site (screenshots will not be accepted). tripadvisor will respond with permission to go live and your key will be upgraded to allow 10,000 calls per day.
for more details please visit : https://developer-tripadvisor.com/content-api/