چرا هر کدی تو ترمینال مینویسم خطای زیر رو میده؟

gradle : The term 'gradle' 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.

At line:1 char:1

+ gradle init

+ ~~~~~~

  + CategoryInfo     : ObjectNotFound: (gradle:String) [], CommandNotFoundException

  + FullyQualifiedErrorId : CommandNotFoundException