Visit https://developer.channeladvisor.com/requesting-a-developer-account
1st Step:
Register with Channel Advisor and Apply for a Developer Account
2nd Step:
Get Application ID and Shared Secret
3rd Step:
After obtaining the Application ID and Shared Secret. Go to Settings >> Channel Advisor. Edit the Application ID and Shared Secret fields
4th Step:
Access Catalog >> Channel Advisor
Authenticate to obtain the authorization code and access token