Cannot add dot executable to system path

[bobsmith76]

When I run graphviz

https://graphviz.readthedocs.io/en/stable/

I get the following error

graphviz.backend.ExecutableNotFound: failed to execute ['dot', '-Tpdf', '-O', 'test-output/aoc.gv.pdf'], make sure the Graphviz executables are on your systems' PATH

I don't know what the graphviz executables are. In any case, my best guess is that I have to add the path of the module that uses graphviz or I have to add the graphviz module to my .bash_profile. Currently, my bash_profile has this line:

PATH="/Library/Frameworks/Python.framework/Versions/3.6/bin:${PATH}

So I tried adding the path of where the module that uses Graphviz is located which is

/Users/me/PycharmProjects/inference_engine2/inference2/proofs/other/use_graphviz.py

Plus the graphviz module itself which is:

/library/frameworks/python.framework/versions/3.6/lib/python3.6/site-packages/graphviz/

Making the final product to be:

PATH="/Library/Frameworks/Python.framework/Versions/3.6/bin:${PATH}:/Users/me/PycharmProjects/inference_engine2/inference2/proofs/other/use_graphviz.py:/library/frameworks/python.framework/versions/3.6/lib/python3.6/site-packages/graphviz/"

But that did not work. I need to know what string I have to add to the PATH.