You must provide the Profile IDs of the accounts in question. Instructions for this can be located here:
Once this has been provided to GFS IT Support, they will perform a request to the Channel Advisor API. You will then need to confirm your approval so that future requests can be accepted.
GFS IT Support will then provide a list of carriers/service codes which must be present in the Channel Advisor “Account Shipping Carriers” section. If they do not appear, the shipping confirmation updates will fail.