REST API - Access Denied

Summary

REST API - Access Denied...but not in Postman

Content

Hello,

attempting my first usage of data from the REST API, a simple analyticsReportResults call. Using Postman to help form the API call, basic auth, and it runs great in Postman, returns fast, gives me exactly what I expect. I move this to the application I want to run it in, Javascript call....and I get an "Access is denied" error. Same PC, same IP etc. Any help for a first timer is appreciated.

Thank you.