Zoho Projects free trial (Premium/Enterprise)

Hello,

we consider use Zoho Projects, Zoho Reports and their integration add-on for our company, but we need to test, how it works.
Integration add-on is only available with paid version of Zoho Projects, so I am curious if I can upgrade my Zoho Projects in any way to test it.
I searched Zoho Projects FAQ, forums and google for such trial, but didn't found any information.

Thanks in advance,
Eve