If condition with CTE in sql

I am trying to Create a view where i need to put condition on year and I am trying below code but I get an error. Can someone please suggest if its possible . And the output which is required I have to use CTE only.
Error is as below : incorrect Syntax near ‘if’

Code is as below :

Declare @year varchar(20)
Set @year = ‘2022’;
With CTE as 
( 
    If @year = ‘2022’ 
    Begin 
    (
        Select 
            @year , 
            Prev_date = (select    DATEADD(month, -1,GETDATE()))
    )
End; 
Else 
  Begin 
(
Select @year,
Prev_date=  (select    DATEADD(month, -2,GETDATE()))
)
  End;
)
Select * 
From CTE

IF, BEGIN and END are related to the procedural code, and cannot be used in this context.

Your code, without further specification, can be replaced with the following:

DECLARE @Year varchar(20);
SET @Year = '2022';
WITH CTE AS
( 
    SELECT Year = @year,
        PrevDate = DATEADD(month, -1,GETDATE())
)
SELECT * 
FROM CTE;

A note and a piece of advice: it looks (am I wrong?) that you are at the beginning of the learning. Try to keep coding guidelines for SQL Server, please. I have made some quick improvements. An example link to follow: https://blog.sqlauthority.com/2008/09/25/sql-server-guidelines-and-coding-standards/

I'm not entirely sure what you want to achieve with your cte, but concerning the condition, you can try to put the following into your view / query / whatever:

Declare @year varchar(20)
Set @year = '2022';
SELECT [year] = @year, [prev_date] = DATEADD(month, -1 * CASE WHEN @year = '2022' THEN 1 ELSE 2 END, GETDATE())

You can use simple effective query rather than going for CTE which should be used for complex queries.

Declare @year varchar(20) Set @year = '2023';
select @year [Year], prev_date = case when @year='2022' then  (Select  DATEADD(month, -1,GETDATE())) else     DATEADD(month, -2,GETDATE()) end

You have not give the error and what database you are using.
I suppose you sql should be syntax error, please try this

Declare @year varchar(20)
Set @year = ‘2022’
With CTE as 
( 
    If @year = ‘2022’ 
    Begin 
    {
        Select 
            @year , 
            (select DATEADD(month, -1,GETDATE())) as previous_date
    }
    END;
)
Select * 
From CTE

BEGIN ... END; must use with {..} in the case use have multiple statments in between.
Hope this help.