There is not option in prestashop for uploading themes, help!

Hi guys i have a problem, i spended $70 buying a prestashop theme but when i go to the “Theme” menu in my prestashop admin panel it says this:

"Can I add my own theme?

Please note that for security reasons, you can only add themes that are being distributed on PrestaShop Addons, the official marketplace."

There is not option to upload the theme i purchased from themeforest.
I tried installing the theme via FileZilla FTP Client, but after installation, when i go back to the theme menu on my admin panel the theme doesn’t appear.

Need help urgently, please.