I am able to get the Security Token via connecting to URL
https://login.microsoftonline.com/extSTS.srf. However I'm stuck with getting the FedAuth cookies. From the resources I've checked you need to send request to "
https://[yoursharepointsite].sharepoint.com/_forms/default.aspx?wa=wsignin1.0, however I get response like following
[USER] does not have permissions to access this resource
Is there a missing set up on the User Account I am using or additional set up needed on the site?