Terminal [`Add` Command is not working ] error when open terminal

Hi,

I am trying to work with React Native and kept running into a prompt that I needed to install expo cli...after answering Y to the install several times and watching it install then run the prompt again I tried to hard in stall with npm install expo-cli --global, which also failed. The next steps were to follow these instructions to set set PATH ....I think this is where the error is coming from, but I can't find help on how to fix and still looking for help with the expo cli as well, I had expo cli working as I have used react native before but then upgraded my system to Mojave and am now having issues if anyone has any insight as well.... back to the question at hand, these are the commands I followed from https://docs.npmjs.com/resolving-eacces-permissions-errors-when-installing-packages-globally

mkdir ~/.npm-global

npm config set prefix '~/.npm-global'

export PATH=~/.npm-global/bin:$PATH

source ~/.profile

npm install expo-cli --global

npm start did not work after doing so and now everytime I open my terminal I get this error message:

-bash: Add: command not found

add seems to be working ok that I can see, just not sure why the error is always there

Please help!! Been seeking guidance for over a week now!

Thank you!

Beth