aah, you are very perspicacious. So the 112's are Imports and 113's are files.
Now I have probably uploaded the file. Next I'll try to import it
Now the whole path works! To document whole path, here is the Import task. That went trough without any complications. Thank you @ben_speight
I am getting the same error. I repeated the steps as suggested by Henri.
Below is the URL I am using.
This is what I am doing to upload the file. This is Postman tool.