Cannot find specified version with pyenv function

I tried to use python in MATLAB with pyenv in Linux system. The Status initially is NotLoaded but everything else looks correct to me as shown below:

Following the example, I typed pyenv('Version','2.7'), received following error:

Status is still NotLoaded. I tried using py.list({'a','b'}), but received: "Unable to resolve the name py.list"

Linux doesn't have Pyenv from Github installed but has wrapper intepreter, executable and library. Works with PyCharm IDE.