Upload photos to the Portfolio collection from an iPhone

I'm currently in the trial period using the ORANSSI template and I have a question.  I'm using the Portfolio collection and I'm trying to create new projects and upload photos from the iPhone app but I don't see the option to upload photos nor the option to create new projects.

Can someone please confirm that it's not possible to create and upload photos to the Portfolio collection from the iPhone app?

If that's not possible what would be the right template alternative to be able to create a similar page of projects and add photos. One of the requirements from my client is that he needs to be able to create new projects to show some pictures directly from his phone.

Any help will be greatly appreciated.

Thanks

Thank you for your comments.  My question is specifically for the Squarespace template called ORANSSI, I feel you provided a generic answer, I'm familiar with WordPress, Joomla, and other CMS systems as well as proficient with HTML/CSS/JS, but in this case, I want to start using Squarespace. I cannot find any documentation for the ORANSSI template.