install node modules from terminal
sudo npm install -g appium --unsafe-perm=true --allow-root
Open the terminal and type :
export ANDROID_HOME=/Applications/ADT/sdk
Add this to the PATH environment variable
export PATH=$PATH:$ANDROID_HOME/bin
export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_161.jdk/Contents/Home
export PATH=$PATH:$JAVA_HOME/bin
mac permission
sudo chown -R $(whoami) /Users/dipjyoti.metia/node_modules