1. Click on Setup > Developer Space > Connections 
   
2. Click Create Connection
   
3. In the Pick Your Service section, under Pre-Defined Services find and select Zoho OAuth
   
4. In the Connection Details section, add zohodesk as the Connection Name and Connection LinkName
   
5. In the Choose Scopes list, select all values that start with 'Desk.' and ending with '.ALL' and then include Desk.search.READ, Desk.products.READ
   
6. Click Create and Connect
   
7. In the page that appears, click Connect
   
8. If you have more than one portal associated, select the Portal to which this connection should be added and click Accept. 
   

Contact Name: Sundar

To extract the value of the Order Number from the above email, proceed with these steps: 

1. Go to Setup, and under Automation, click Workflows.
   
2. On the left panel, under Workflows, click Rules > Create Rule.
   In the Basic Information section, carry out the following steps:
3. In the Module drop-down menu, select Tickets.
   
4. Enter a name and description for the rule.
   
5. If you want to activate the rule right away, select the Active checkbox. Else, you can just create the rule now and activate it later, on the Rules page.
   
6. Click Next.
   In the Execute on section, perform the following steps:
7. Select the Create checkbox to execute this rule every time a new ticket is created. 
   
8. Click Next.
   In the Criteria section, do not select any criteria and move to the next section.
   In the Actions section, carry out the following steps:
9. Click the + icon and select Custom Functions > New
   
10. Click Edit Arguments
    
11. In the Name field type TicketID, and from the Value drop-down list select Ticket Id under Ticket Information.
    
12. In the script window, input the Custom Function you find below:
    orgId = "paste orgId here";
    fromWord = "Order Number:";
    toWord = "Contact Name:";
    lenfromWord = fromWord.length();
    T_Info = invokeurl
    [
    url :"https://desk.zoho.com/api/v1/tickets/" + TicketID + "/latestThread?include=plainText"
    type :GET
    connection:"zohodesk"
    ];
    plainText = T_Info.getJSON("plainText");
    orderNumber = plainText.subText(plainText.indexOf(fromWord) + lenfromWord ,plainText.indexOf(toWord));
    updateTicket = zoho.desk.update(orgId,"tickets",TicketID,{"cf":{"cf_order_number":orderNumber}});
    info updateTicket;