Prefill Form Field - Form Builder

I have created a technical support survey form. I'm using OSTicket for my tech support ticketing system.

I want to pre fill one item in my form (Ticket Number). I know this is normally done in the URL but I cannot seem to get the URL code correct.

Here is the URL with the code I'm trying to use:

The original page url is:

Is there anyone that can help me understand what I'm doing wrong? I have tried using the label “elm_240” and also "form_values[240] in place of “Ticket%#”.

Here are the form properties from the code:

Thanks so much in advance if you can assist!

I'm trying to create a link to a form from a product which when clicked auto fills in the product name in the form, how can this be done?

Try some jQuery like:

]code] ```

If you can add product_id to the URL, use



where elm_240 is the ID of the required text input