Proxy error: Could not proxy request /signup from localhost:3000 to http://localhost:8080/. [client] See https://nodejs.org/api/errors.html#errors_common_system_errors for more information (ECONNREFUSED). code example

Example 1: react proxy error: could not proxy request from localhost:3000 to http localhost:5000 econnreset

"start": "./node_modules/.bin/concurrently \"./node_modules/.bin/nodemon\" \"npm run client\"",

Example 2: react proxy error: could not proxy request from localhost:3000 to http localhost:5000 econnreset

"start": "./node_modules/.bin/concurrently \"npm run server\" \"npm run client\"",