Hi Bernd ,
As always from Download section >> https://www.joomshaper.com/downloads/template?search=helix
Click DOWNLOAD button next to Helix Ultimate, then in Popup Window choose row with Template name and click "Download" , that's all.

As you see it's in the same area from where you can download Quickstart.
Template package includes template+helix plugin, but no demo data! Later switch as default template. On YouTube you can find some guides, if you prefer watch than read documenation.
https://www.joomshaper.com/documentation/helix-framework