How to install orca in Ubuntu 18.04

I am the python library called plotly on Ubuntu 18.04 and Python 3.5.6

I need to export the graphs as eps files. I use this line:

fig.write_image("images/fig1.eps")

But this generates an error by my python code saying:

If you haven't installed orca yet, you can do so using conda as follows:

    $ conda install -c plotly plotly-orca

When I try to execute the above command, I get error:

conda: command not found

When I try to install conda using:

sudo pat-get install conda

I also get error saying it can not find this pacakage.

Can anyone help me please install conda so I can use it with plotly library?