hey, can anyone help me the problem i am facing with react native unable to use ‘expo start’ so here it is that pop-up

I have npm installed
C:WindowsSystem32task1>npm -v
I have node install
C:WindowsSystem32task1>node -v
this keep pop up
C:WindowsSystem32task1>expo start
‘expo’ is not recognized as an internal or external command,
operable program or batch file.