Question Error in Unity Package Manager

Hello,

I copied ML-Agents-Master on C:\ and now I want add ML-Agents plugin in my unity through Unity Package Manager. When I do it I get a error message !
how can I solve it ?

error message is :

Cannot perform upm operation: Unable to add package [com.unity.ml-agents@file:C:/ml-agents-master/com.unity.ml-agents]:

  Package com.unity.ml-agents@file:C:\ml-agents-master\com.unity.ml-agents has invalid dependencies:

    com.unity.barracuda: Package [com.unity.barracuda@0.6.1-preview] cannot be found [NotFound]

UnityEditor.EditorApplication:Internal_CallUpdateFunctions()

 

There is not anybody that help me ?!