If you are Cisco internal, please look at the NSO field portal for assistance.
If you are Cisco external current customer you should have entitlement at software.cisco.com. If you are not yet a customer you should reach out to your account team or partner contact.
I am afraid I am not sure, emailing whoever you got it from might be the best idea. Have you made sure to check software.cisco.com and that you do not have an entitlement there?
NED download from software.cisco.com is for customers who have paid for the NEDs. Partners can access software via the NFR program: Partners – Two Ways to Get Non-Production NSO Software