Download PNG From AWS Hosted App

Dash Python
1

My app is hosted on AWS and I want the user to download a pre-generated seaborn heatmap available in a folder (viewable by the app but not necessarily in the same directory).

Here is my code:

html.Div(children=[html.A(id='heatmap_url')]),

and the callback whiich updares this:

@app.callback([Output('heatmap_url', 'href'),
              Output('heatmap_url', 'download'),
              Output('heatmap_url', 'children'),
              Output('heatmap_url', 'style')],
             [Input('stored-url','children')])
def get_download_link(output_msg, heatmap_link):
    heatmap_link, heatmap_file, heatmap_text = '', '', ''
    style = {'width':'150px', 'text-align':'center', 'padding':'0px', 'display':'none'}
    if stored_url != '':
        heatmap_link = session_variables[stored_url]['heatmap_url']
        heatmap_file = heatmap_link.split('/')[-1]
        heatmap_text = 'Download: %s' % heatmap_link
        style = {'width':'150px', 'text-align':'center', 'padding':'0px'}
    return heatmap_link, heatmap_file, heatmap_text, style

context: In another callback I check if the file exists. If not, the output for 'stored_url', 'children' becomes ''.

stored__url is something like: /D/user/home/documents/heatmap_name.png

I can get the browser to download a png with the correct name, but when I open the file it says: heatmap_name.png It looks like we don't support this file format. in my native Windows 10 Photos app. I tried opening it in Paint, uploading it to Google Drive, nothing worked.

How can I get the user to view the image? I was originally using html.Img but the images are too big for my app.

Can I perhaps get the user to open the PNG in a new window by clicking the link?