Trello - 401 Unauthorized while trying to mark notification unread=fase?

[MPippin]

I'm a heavy API user, so I have covered the basics. Token/Key works fine for other endpoints. 

I'm testing here, and issue is reproducible:

https://developers.trello.com/reference#notificationsid-1

When targeting seemingly ANY notification for my users (source of API token), I always get a 401 Unauthorized response, if I set the value - as if I don't have permission to modify my own notification?

Using this endpoint also fails, with 401.

https://developers.trello.com/reference#notificationsidunread

Ultimately, I'm trying to auto "read" a particular type of notification.

[MPippin · Accepted solution]

This has been resolved - the token I was using did not have account level write permissions - doh!