Can't upgrade to GP premium from free version

Hi,

First, I build a complete page using the free version. After some thought, I decided to purchase the premium. According to the instructions on this page:

https://docs.generatepress.com/article/updating-gp-premium/

All I need to do is find the 'updates' box under appearances--->Generate Press.

No such box exists.

The second option is to install 'Easy theme and plugin up upgrades' which I did. After activating the plugin, I attempted to install the premium theme, but received this error:

The package could not be installed. The theme is missing the style.css stylesheet.
Theme installation failed.

Please advise.