Pulling a record in a custom contact field to a custom ticket field

Hello Everyone,

I am trying to know on how do I pull information(in a custom field) from a contact so it automatically updates when I fill in a ticket using the contact name?

Example:

When I lookup an account:

It auto populates the other fields such as Account Name, Email, and Phone#

What I am trying to achieve is for the custom field(Subscription Tier) in the contact info:

To be automatically filled in the ticket when I pull up the user:

I have been provided with a code and a set of instructions but when testing with emails that are in the contact list, it still doesn't populate even when the custom function triggers:

ORGID = xxxxx;
info zoho.desk.update(ORGID, "tickets", ticketID,{"cf":{"cf_subscription_type":customfield1}}); Argument Mapping:
ticketID --> Ticket Id
customfield1 --> IFS (Contacts Module )

Maybe I was not doing it correctly. Please let me know.

Also I'm wondering if there are any other solutions to this? maybe someone has the code for the email lookup field and I can just "replace" the code with the necessary fields such as my custom field?

Thank you.