To use viator tours booking module please follow the below instructions 

1. Signup at viator partners site at : https://www.partner.viator.com/partner/register/register.jspa
2. Once your account verification and approved please login to your account and edit the theme according to your needs 
3. Then from homepage you can find your viator partner ID see as below screenshot 
4. Copy the last right side numbers only from your partner URL for web
5. Navivate to modules and enable viator module and then click on settings 
6. From settings page paste your viator web and mobile URL
   
   that's all conguratulations you have successfully enabled viator for your website.