Unable to run the sample

[dkarthi1973]

E:\karthi\workspace\node-red-react-example-master>npm run start

node-red-react-example@1.0.0 start E:\karthi\workspace\node-red-react-example-master
nodemon --watch pallets --watch src/client --exec 'npm run build-all'

[nodemon] 1.17.5
[nodemon] to restart at any time, enter rs
[nodemon] watching: E:\karthi\workspace\node-red-react-example-master\pallets//* E:\karthi\workspace\node-red-react-example-master\src\client//*
[nodemon] starting 'npm run build-all'
''npm' is not recognized as an internal or external command,
operable program or batch file.
[nodemon] app crashed - waiting for file changes before starting...