Unable to display graph with data from upload component


I would like to create an app in which the user uploads a csv file and then the csv data is used to display a line plot, however, even though the code has no errors, the graph only shows its axis without displaying the data from the uploaded file. I’m starting to feel desperate about this since I can’t find any solution.

I have to confess that I’m not a very experienced programmer so I would be very thankful if I could get any help.

Best regards.