Answer by pjcunningham for Serve an ical feed with Flask

You need to set the the correct content disposition header of the response. In your case the header would be something like the following:

Content-Disposition: attachment; filename=calender.ics;

In your Flask route your code should look something like the following:

from flask import make_responseapp = Flask(__name__)# ...@app.route('/calendar/')def calendar():    #  Get the calendar data    _calendar = make_calendar()    #  turn calendar data into a response    response = make_response(_calendar)    response.headers["Content-Disposition"] = "attachment; filename=calendar.ics"    return response