my profile did not had permissions to access marketing api reports.
for 401 Unauthorized you might be not passing correct access token.
Steps are : Get authorization code using the below url
https://www.amazon.com/ap/oa?client_id=YOUR_CLINET_ID &scope=cpc_advertising:campaign_management&response_type=code&redirect_uri=YOUR_REIRECT_URL(the one which you have setup using register application in login with Amazon
the above url redirects to the redirect url with authorization code param
pass authorization code in the below url
curl -k -v -X POST -H “Content-Type:application/x-www-form-urlencoded;charset=UTF-8” --data "grant_type=authorization_code&code=AUTH_CODE&redirect_uri=YOUR_REDIRECT_URL&client_id=CLIENT_ID&client_secret=CLIENT_SECREThttps://api.amazon.com/auth/o2/token
the above one gives access token which you need to pass toget profiles.
HOPE THIS help.
all the steps are mentioned in the below url