Is there a way to download "Responses In Progress" survey from Qualtrics?
Not through the API.  You can do it manually through the Qualtrics interface.
If you need to use the API and the survey is invite only, an alternative would be to download the distribution history for all the distributions. That will tell you the status of each invitee.
I'm looking for a way to download surveys that are still open on Qualtrics so that I can create a report on how many surveys are completed and how many are still in progress. I was able to follow their API documentation to download the completed surveys to a csv file but I couldn't find a way to do the same for the In Progress surveys. Thanks in advance for your help.