Problem with Images API - the image file is not uploaded to the system and it size equals few bytes (Entry created)

so I use next.js I installed contentful-mangement

I used this code:
[Content Management API | Contentful]
I used 1:1 code from documentation: Upload a file

Even though i used exactly the same code (both using zsh: node [external file] and I tried run this code in a component). After run this code I receive response that images is uploaded, I get an ID and all from sys. What is more in Contentful i see the entry but without thumbnail.

You can see that it looks like the file is not uploaded to the system, when i check info on this entry i see it size equals only few bytes.

When i inspect the image and go under the link from ctfassets i see something like this:
“This XML file does not appear to have any style information associated with it. The document tree is shown below”
And i see file from the documentation:
file: ‘’

When i try to upload png/jpg file i see a very very small white square png.

To be honest i dont know what i’m doing wrong over and over again.
Any idea or suggestion how i can send this image to contentful?