Subgraph fails to initialize

I am trying to use The graph, after successfully installing the graph Cli with, yarn global add @graphprotocol/graph-cli,
my vscode fails to initialize my subgraph with graph init --studio nft-marketplace

this is what i got as output

graph : The term 'graph' is not recognized as the name of a cmdlet, function, script file, or operable program.
 Check the spelling of the name, or if a path was included, verify that the path is correct and try again.