Golang - fiber GraphQL subscriptions

I am struggling with a piece of code that uses gqlgen and go fiber to create subscriptions.

This should solve it but I can't implement it
https://stackoverflow.com/questions/62980183/response-does-not-implement-http-hijacker

I am getting this error message where the http responder needs to be upgraded to use sockets.

unable to upgrade *fasthttpadaptor.netHTTPResponseWriter to websocket websocket: response does not implement http.Hijacker:

func graphqlServer() fiber.Handler

srv := handler.New(generated.NewExecutableSchema(generated.ConfigResolvers: &resolvers.Resolver))

srv.AddTransport(transport.Websocket
KeepAlivePingInterval: 5 * time.Second,
Upgrader: websocket.Upgrader
CheckOrigin: func(r *http.Request) bool
return true
)
srv.AddTransport(transport.Options)
srv.AddTransport(transport.GET)
srv.AddTransport(transport.POST)
srv.AddTransport(transport.MultipartForm)


srv.Use(extension.Introspection)