Step 1. Generate a Zoho API token

https://www.zoho.com/developer/help/api/using-authentication-token.html

Sample response 

#
#Wed Feb 29 03:07:33 PST 2012
AUTHTOKEN=1000397765.1000414544.ca1f9949f637a8e667e35bd3654bf82e0c70975ee47349dc57aa7967b151a11a9ea419459381cd82e5757e644904df3315a6a729d528538df406f598c9e4f7f2
RESULT=TRUE

Step 2.Setup iHub credentials

1. Once generated goto Credentials, select Custom Headers and enter a name like Zoho API Key
2. Click Add to add a new row
3. In the key field add Authorization
4. In the value  key generate from the step above, example 1000397765.1000414544.ca1f9949f637a8e667e35bd3654bf82e0c70975ee47349dc57aa7967b151a11a9ea419459381cd82e5757e644904df3315a6a729d528538df406f598c9e4f7f2

 Step 3. Fetch Records from the "Leads" Module

1. Goto integrations and click Create
2. Enter a name and select application/json as template
3. Select Method POST
4. Enter URL https://<APPDOMAIN>/crm/private/xml/Leads/getRecords&scope=crmap
5. Select the Authentication called Zoho API key created in step 2.

Step 4. Test & verify

Click test and view the execution log