How does your collaboration with Dropbox works, like in payment part?

I'm not sure I understood your question clearly.

When you register an account in JotForm and create your form, all the integration and features that JotForm offers are free to use.

As far as I know,dropbox doesn't involved payment integration. However, if you are referring to its paid plan, you may refer to the Dropbox website https://www.dropbox.com/help/billing.

You can check this guide regarding Dropbox Integration:https://www.jotform.com/dropbox/

Thank you.

hey if i want to upload videos, how does that happen ?
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I can see that you already opened a separate thread for this issue. Please wait for our reply on this thread: https://www.jotform.com/answers/1590538.

Thank you.