How to download attachment with oauth token

[Paul Woods]

I'm trying to download the content of attachments on Confluence Cloud using the download link ( fetched from an earlier call to get the attachment infomation )

https://api.atlassian.com/ex/confluence/xx/wiki/download/attachments/94..45/filename.txt?version=1&modificationDate=1584525504744&cacheVersion=1&api=v2

The result is a 401 "Token is missing required scopes: confluence:atlassian-external"

I'm using OAuth tokens here - any idea how to get this working? All the examples I can find are using basic auth, is this the only supported mechanism?

thanks

Paul Woods