Template edit, link slides together

Hello,
I’m working in localhost. I use one of the free HT templates and I want to have 3 sliding images for my homepage hero.
I edited each slide individually in Elementor, but I don’t find any option to actually link them together. When I drag the HT Slider widget into the Elementor editor, I get the following error: “The template id cannot be the same as the currently edited template”.
I really don’t know how to make it work, as I haven’t found some clear documentation.
Thank you for the help.