sql bigger parameter then specyfied - no error - just taking substring? why?

I have some sql procedure (MSSQL 2019) if relevant

Create PROCEDURE [dbo].[test] @tmp varchar(32)  AS
print @tmp

why when i do

EXEC	@return_value = [dbo].[test]
		@tmp = N'SSL99999999999999999999999999999900000006785999999999999999'

I se it use 32 chars substring in @tmp ? SSL99999999999999999999999999999 And no exception that string or binary data would be truncated as i expected ? Can i turn on such behavouur ? i would need this if possible ;) Thanks and regards !