How to apply alias in @key field in apollo federation

type oPlayer @key(fields: "id") @key(fields: "name"){
 id:ID
 name: String
}
extend type oPlayer @key(fields: "name") @key(fields: "PlayerId") 
{
 name: String @external
 PlayerId: ID @external
}

I am tring to resolve that field using PlayerId field with id but I am not able get data in referance resolver How to provide alias to "PlayerId:id" so oPlayer type can resolve field
I want that apollo federation allow to give alias for PlayerId to id so it can easily resolve fields