Auto-fill Text Field on Ticket from User Text Field

Hello,
 
My name is Jakub and I am contacting you from Zendesk. From what you said, I've noted you would like to map user fields to custom ticket fields.
 
This is possible but will require some development on your side, as this is not a straight out-of-the-box solution. Please note Zendesk does not support or guarantee custom code as this fails outside of our support scope.
 
These steps are only for instructional purposes:
 
1. Create a webhook and select Triggers and Automation (screenshot)
 
In the name put whatever you want to call it, in Endpoint put: https://chimecrm.zendesk.com/api/v2/tickets/{{ticket.id}} , Request Method PUT, Format JSON and the method you want to authenticate it with.
 

 
2. Create both fields, ticket and user field, if you already have them, skip this step. We will need the field id and user field key:
 

 

 
3. We need to create a trigger that will make a call to our webhook whenever a set of conditions is met, so you can set whatever you want this action to trigger, I only set the Ticket is Updated for test purposes:
 
The actions is what matters here, select Notify an active webhook and the webhook you created in step 1. Put there:
 
{
"ticket": {
"custom_fields": [{ "id": 19355046105108, "value": "{{ticket.requester.custom_fields.user_field}}"}]
}
}
 
This is important, change the id for your ticket field id, and in the value placeholder the last part after custom_fields you need to put the user field key I have shown you before.
 
That's done!