How to run nodejs and react at the same time?

Question

npm

There are two projects that are in the same folder:
-Folder;
--api;
--client;

I want to run them through api, for example. But I can’t reach the client, I don’t know how to go into its folder and run it.

"backend": "nodemon server.js",
"client": "cd ..; cd ./note-manager && npm start && npm start",
"fullstack": "concurrently -n 'server, client' \"nodemon server.js\" \"npm run client\""