Integrate bitbucket with C#

[kefah aleesa]

I want to integrate my c# service with bitbucket cloud by using rest API so I can 

Fork repositories
create branches 
edit files 
Grant users as admin to the new repositories
I found that the Atlassian.Stash.Api library is the best for that
But I feel confused by the authentication method should I use
the library does not support the Oauth2 authentication and the basic authentication its not working  I keep have this error :

One or more errors occurred. (Unexpected character encountered while parsing value: T. Pat

so can you help if Atlassian.Stash.Api  supports Outh2 authentication ?  and what the best way to integrated with bitbucket using c# 

Thank you 

[Nic Brough _Adaptavist_]

This suggests your code is not sending valid text to the server when you make the rest call.  You'll need to work out what is is sending and why replace the "T.Pat" it is sending with something valid.