ارور در enable-migrations

سلام وقت بخیر 

نگامی که enable-migrations رو مي زنم با خطای زیر موتجه میشم 

PM> Enable-migrations

Enable-migrations : The term 'Enable-migrations' 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

+ Enable-migrations

+ ~~~~~~~~~~~~~~~~~

   + CategoryInfo          : ObjectNotFound: (Enable-migrations:String) [], CommandNotFoundException

   + FullyQualifiedErrorId : CommandNotFoundException

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