@Karachay You should have a Plotly account to post the plot on the Plotly cloud. To sign up go to this page:
https://help.plot.ly/how-to-sign-up-to-plotly/ and click on SIGN UP, in the upper right corner.
Once you have an account choose Settings from the upper right dropdown menu, and then click on the API keys and Regenerate Key. Copy the generated key and save it somewhere to use it when you post a new plot. Namely, sign in via the line of code, inserted before py.iplot():
py.sign_in('your_username', 'your_API_key)
That’s all 