This error is related to Windows Line endings being different from Unix ones. Try running npx prettier --write . on your project's directory. This command will tell prettier to fix simple errors (such as this one) when found.

To prevent this error from happening again you can either set "end-of-line" to auto on your .prettierrc file or try setting line endings to "Unix"/LF on your editor: instructions for VSCode and for IntelliJ-based editors

There's a great package called prettier-eslint that we've used at work before. It will format using prettier and then run eslint --fix on your code. We liked it, give it a try!

Installing a module that includes a CLI program like prettier, nodemon, etc., will place the program in node_modules/.bin. Your terminal shell does not know to look in this folder when you run a command. Type echo $PATH in your terminal to see a list of the folders that are checked when you run a command. You'll see that running prettier will be looking in places like /bin, /usr/bin, /usr/local/bin, etc., but definitely not /var/folders/q6/npwl_7xj4wg91lg06f8pnnfh0000gn/T/node_modules.

This is why npx is often used; from their docs:

Executes either from a local node_modules/.bin, or from a central cache, installing any packages needed in order for to run.

You could also run it via ./node_modules/.bin/prettier, or you could install it globally, as you ultimately did, which will put it in a place that is part of your $PATH.