Package Manager can't install OpenVR Package

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I’m using Unity 2018.4.0f1 and 2019.1.11f1 both of them has same Issues
This is what I get when I download SteamVR in Asset Store.

It said’s I can install the package manually in Package Manager Window but Package Manager also not available whit this message
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Also the console Messages are

1.Cannot perform upm operation: unable to verify the first certificate [NotFound]
UnityEditor.EditorApplication:Internal_CallUpdateFunctions()

2.Error searching packages online.
UnityEditor.EditorApplication:Internal_CallUpdateFunctions()

is there anyone who know to solve these problems or someone have OpenVR package
PLEASE HELP ME

Same problem for me:/
Did you find a solution ?