Hi Marc-Andre. Nice to hear from you again!
The reason your site isn’t showing the menu is because you have your homepage set to be a post. If you use the Jorgen grid as your homepage (instead of the post you specified), AND have checked the box to “Enable Front Page Header”, the menu icon will show on the top right.
Alternatively, pages will show a menu icon (example: https://playground.aesopstories.com/sample-page/) but posts do not.