Hello @romerol3 Welcome to the Canvas Community. Thank you for posting your question. I am not sure that I completely understand your question. Files are not submitted to the dashboard for assignments in your course. Assuming that you are a student, you would submit a file as an attachment to the actual assignment in your course. I would first recommend that you take a look at these two tutorial videos:
Next, you can take a look at these written Guides if you want to dive a bit deeper into assignments.
I hope these resources will be of help to you, Luis. Please let Community members know if you have any questions about this information...thanks!
Like @chofer I was a little confused by your question. His tips are super helpful.
I was wondering if you were trying to put an image into your course card on your Dashboard.
That can get a little confusing when you try to drag the file there. If that's the case here's the guide for that https://community.canvaslms.com/docs/DOC-12780-4152626354 And when it comes to drag and dropping your image I usually minimise my Canvas screen if I'm working on one screen. Then drag the image into Canvas that way.
Hope that helps.