JavaScript section is for sure available for trial version.

Are you sure you haven't chosen the "Responsive Form" option at the beginning? There indeed is no such option.

I see no attachment under your question, thus I can't tell for sure, that this is the reason

 Regards,

 Tomasz

Yes, that is exactly what I did. Was there a reason why the custom javascript option is not available in mobile forms?

Do not confuse Responsive forms with Mobile forms. Although they are responsive thus will perfectly work on mobile devices their goal is much wider

And the reason why the custom JavaScript is not present there is the must to have their behavior under control. Whereas classic, Standard Forms could have the custom JS present, as they are "fixed" and not much dependent on browser etc. the Responsive are filled up with dedicated mechanisms that operating could be disrupted by a custom JS leading them to malfunction.

You can find my review of the new Responsive forms here.

You can also read about them more here: https://community.nintex.com/blogs/NintexProductBlog/2017/08/14/whats-new-for-forms-for-office-365-july-2017

So if you want to have custom JS, now you have to delete your Responsive form (click the "delete" icon in the Design tab) and start creating Nintex Form once again, this time choose "Standard" form.

Regards,

Tomasz

Got it! Thanks Tomasz for the clarification on the differences between the form types.

If you find my answer as correct, please mark it as the solution for your question.

Thanks!

Tomasz