Hello, @danielkue,
1. Actually, you are using the WP Bakery page builder on your site, and the Progress Bar you shared the URL: https://xstore.8theme.com/elementor/demos/minimal-fashion02/linear-progress-bar/ is for the Elementor page builder.
We have the Progress Bar element in the WP Bakery page builder as well but unfortunately, we do not have such options for the thickness of the bar in the WP Bakery version.
So if you want to use that bar style, you have to use the Elementor page builder for your site from the scratch and then you will be able to simply copy and paste the particular style on your site by watching this video: https://www.youtube.com/watch?v=MYei56eV7mU
For now, I have added the Progress Bar WP Bakery element on your site by creating a test page here, you can check the possible options for it: https://shop.biochar.de/test-page-2/
2. I have created the same style selection bar from the marketing demo on your site test page here, please check it: https://shop.biochar.de/test-page-2/
Regards 8Themes Team.