How do i declare a user defined table type sproc parameter as a local variable?

I have a procedure that uses a user defined table type.
I am trying to redeclare the @accountList parameter into a local 
variable but it's not working and says that i must declare the 
scalar variable @accountList.
this is the line that is having the issue: must declare the 
scalar variable @accountList
SET @local_accountList = @accountList

ALTER PROCEDURE [dbo].[sp_DynamicNumberVisits] @accountList AS integer_list_tbltype READONLY
        ,@startDate NVARCHAR(50)
        ,@endDate NVARCHAR(50)
AS
BEGIN
    DECLARE @local_accountList AS integer_list_tbltype 
        DECLARE @local_startDate AS NVARCHAR(50)
        DECLARE @local_endDate AS NVARCHAR(50)

        SET @local_accountList = @accountList 
        SET @local_startDate = @startDate
        SET @local_endDate = @endDate


-------------------------------------------------------
CREATE TYPE [dbo].[integer_list_tbltype] AS TABLE(
        [n] [int] NOT NULL,
        PRIMARY KEY CLUSTERED 
(
        [n] ASC
)WITH (IGNORE_DUP_KEY = OFF)
)
GO