Array As Parameter

hi guys im having some problems with arrays as parameter
what i want to do is pass a array of comma separated values i.e 12,24,36 and use the in(@parameter) but it doesnt work

i've found some solutions, like
ALTER PROCEDURE [dbo].[GetLawyers] ( @LawyerTypeIDs VARCHAR(100)
AS

DECLARE @SQL VARCHAR(2000)

SET @SQL = 'SELECT * FROM [dbo].[TB_VALOR_BANCOS]
WHERE [PARCELAS] IN (' + @LawyerTypeIDs + ')'
EXECUTE (@SQL)

but in my case doesnt work.

here is a part of my code
SELECT * FROM (
SELECT *, ROW_NUMBER()
OVER (PARTITION BY cod_banco ORDER BY coeficiente asc) AS RecID FROM tb_valor_bancos
where
(1 = CASE WHEN @TABELA IS NULL THEN 1
ELSE CASE WHEN TABELA = @TABELA THEN 1
ELSE 0
END
END
)
AND (1 = CASE WHEN @PARCELAS IS NULL THEN 1
ELSE CASE WHEN PARCELAS in(@PARCELAS) THEN 1
ELSE 0
END
END
)
...

i know there is a way to pass the array into a table but it doesnt work too

thanks