feed in a license key

Hi,
I'd need to feed in a license key onto a site.
I used to have the pro version and all of a sudden after an update, I got the lite version.
I looked into the forum and found https://www.joomshaper.com/forum/question/1417 but can't find the "option" to feed in my license number. I only get the "Get Pro version" button from the main menu.
What can I do?
Seems that I don't have a license option, only the "options" and "Rights"