Open '.xlsx' files in the "Diagram" area in Python4Capella case

I was learning how to install Python4Capella on YouTube, and I noticed that the explainer in that video can open ‘.xlsx’ files in the “Diagram” area. The link to that video is Python4Capella Add-on - Demonstration of use cases 2. System Analysis - YouTube, and the exact effect is shown in Figure 1.

As shown in Figure 2, I made a selection of editors.


However, at the moment I get the effect as in Figure 3, which means that the opened ‘.xlsx’ file is outside of the Capella software, instead of the effect in Figure 1 of the video.

So my question is how should I set it up to achieve the effect in the video, which is that it appears in the “Diagram” area when I open ‘.xlsx’ files. I would be grateful for an answer.