flutter : The term 'flutter' is not recognized as the name of a cmdlet, function, script

flutter : The term 'flutter' is not recognized as the name of a cmdlet, function, script , function, script h was included, 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. At line:1 char:1 + flutter mandNotFoundException + ~~~~~~~ + CategoryInfo : ObjectNotFound: (flutter:String) [], CommandNotFoundException + FullyQualifiedErrorId : CommandNotFoundException