CommandNotFoundError: Your shell has not been properly configured to use 'conda activate'.
If your shell is Bash or a Bourne variant, enable conda for the current user with

    $ echo ". /home/ubuntu/anaconda3/etc/profile.d/conda.sh" >> ~/.bashrc

or, for all users, enable conda with

    $ sudo ln -s /home/ubuntu/anaconda3/etc/profile.d/conda.sh /etc/profile.d/conda.sh

The options above will permanently enable the 'conda' command, but they do NOT
put conda's base (root) environment on PATH.  To do so, run

    $ conda activate

in your terminal, or to put the base environment on PATH permanently, run

    $ echo "conda activate" >> ~/.bashrc

Previous to conda 4.4, the recommended way to activate conda was to modify PATH in
your ~/.bashrc file.  You should manually remove the line that looks like

    export PATH="/home/ubuntu/anaconda3/bin:$PATH"

^^^ The above line should NO LONGER be in your ~/.bashrc file! ^^^