You may accidentally add the node_modules or you forgot to add the node_modules directory to .gitignore list, no worry, you may remove it after you pushed to the git.
First, add the node_modules in to the .gitignore
vim .gitignore
After added the /node_modules and save it.
git rm -r --cached .
git add .
git commit -m "remove gitignore files"
git push origin master