How can I create a transparent background?

Well the Question read on Top.

I loaded already a transparent gif as background picture but it didn't help.

what to do or is it impossible?

Please check the steps below to make the background transparent:

1. Click to the "Designer" icon in Form builder.

2. In the Background input, type "transparent" (without the quotes)

3. Click on the Save changes.

You can also check the below guide, which explains different ways to make form background transparent:

https://www.jotform.com/help/87-Making-the-Form-Background-Transparent

If you have any query, or need further assistance, feel free to revert back.

Thanks.