These links might help:
First you need to set up your OKTA to make it point to your Qlikview server. Then you need to make the Getticket.aspx web page (described in one of the articles above) work, meaning it should capture the correct log in id passed from OKTA. This part took me many hours because it is difficult to find the cause of error. I had to create a .NET solution on my local PC based on the Getticket.aspx, and put in code to log real time running information in order to debug. Also, please make sure the setting in IIS and Qlikview server are correct. They are the ones which caused problems in my situation.
Hope this would help.