Why my object's extrude is not the same as in tutorial's one in Inkscape?

Question

I follow this tutorial, when I follow his steps, I get this result

Meanwhile, here is his result

I don't know what making this wrong, I am sure I follow his step by step to this point. Why can this be happening?

Here is my file https://drive.google.com/file/d/18ncgBV8tIlI1O-FTxmqwnPgauUqte7U-/view?usp=sharing

Answer 1

The following was tested using Inkscape 1.2. It seems to work as expected. Here are the steps.

1. Type something

2. Path > Object to Path

3. Object > Ungroup

4. Path > Combine

5. Edit > Duplicate, and set the fill of the top duplicate to something else so you can see it

6. Move the top letters to offset them

7. Select both paths, and do Extensions > Generate from Path > Extrude

Here's the result

Answer 2

You tried to generate an extrusion between 2 combined paths which both contain outline curves of letters I, N and K.

The result is a mess if Inkscape cannot decide right the node correspondence relation between the upper and lower INKs. To get it surely right make at first the lower combined path. Duplicate it and use the duplicate as the upper combined path. This guarantees the identical node order. Randomly collected subpaths very likely have random node order differences for ex. depending on their layering order before making the combined path.

Before applying the extrusion you can move, scale and rotate both inks as needed.