In the downloads folder, locate the ZIP file and right-click, then click ‘expand’. When the file explorer opens, navigate to your project main folder and click that, then Okay or Expand, as such.
Or, simply expand to the present location and move the folder to the location noted above.
Did you manage to UNZIP the project files? Afraid I don’t know anything about Jupyter, never used it. With any luck someone who has done this project will spot your question.