anaconda navigator not start direct without source command
You can write script (.sh) for that.

STARTPATH=$(pwd)
cd ~/anaconda3/bin
case $1 in
    -j|--jupyter)
        shift
        source activate
        jupyter-lab
        ;;
    -n|--navigator)
        shift
        source activate
        anaconda-navigator
        ;;
esac
source deactivate
cd $STARTPATH


Then you can run the script by ./ or you can put the script in /usr/local/bin and make it executable chmod +x *yourfile*.sh. 

After that you should be able to type in your console: *yourfile* -n and this will launch anaconda navigator.