Here is the url without the API key.
http://graph.api.smartthings.com/api/smartapps/installations/dd9677bf-354c-48e8-8a33-d2ca5e4e247c/switches/09235b47-637d-4c54-87be-10ba8c761edb/level/50?access_token=
The unedited link currently dims my light to 50%, I checked before posting.
Looking at back at my notes, I think currently the smart app I am using to get my Endpoint installation code is “Thing Layer” by Jody Albritton.