How to create a dynamic order by query with with multiple fields

I am trying to create a stored procedure with multiple order by fields. The order by field and direction is passed through the stored procedure as arguments.

CREATE PROCEDURE GetFilteredLogs
    @FromDate       datetime2,
    @ToDate         datetime2,
    @SearchText     nvarchar(100) = NULL,
    @LogTypeIds     Ids READONLY,
    @AreaIds        Ids READONLY,
    @SubTypeIds     Ids READONLY,
    @UnitIds        Ids READONLY,
    @SortField      nvarchar(25) = NULL,
    @SortDirection  nvarchar(5) = NULL
AS
    SELECT *
    FROM LogsView
    WHERE   
        (CreatedDate >= @FromDate AND CreatedDate <= @ToDate) 
        AND ((([Text] LIKE '%' + @SearchText + '%' OR @SearchText IS NULL)
              AND (LogTypeId IN (SELECT Id FROM @LogTypeIds) OR NOT EXISTS (SELECT 1 FROM @LogTypeIds))
              AND (OperationAreaId IN (SELECT Id FROM @AreaIds) OR NOT EXISTS (SELECT 1 FROM @AreaIds))
              AND (Subtype IN (SELECT Id FROM @SubTypeIds) OR NOT EXISTS (SELECT 1 FROM @SubTypeIds))
              AND (Unit IN (SELECT Id FROM @UnitIds) OR NOT EXISTS (SELECT 1 FROM @UnitIds))) OR IsCritical = 1)    
ORDER BY
    CASE @SortField
        WHEN 'LogTypeId' THEN CreatedDate DESC(should be passed as argument), LogTypeId DESC
        ELSE CreatedDate DESC
    END

GO

The order by section in the above stored procedure is not in correct syntax. How can I do it and is it possible the way I have tried above?

This is a classic Kitchen Sink Query.

Use dynamic SQL to build up a series of conditions and ordering clauses. Then use sp_executesql to execute it, passing in all necessary parameters.

CREATE OR ALTER PROCEDURE GetFilteredLogs
    @FromDate       datetime2,
    @ToDate         datetime2,
    @SearchText     nvarchar(100) = NULL,
    @LogTypeIds     Ids READONLY,
    @AreaIds        Ids READONLY,
    @SubTypeIds     Ids READONLY,
    @UnitIds        Ids READONLY,
    @SortField      nvarchar(25) = NULL,
    @SortDirection  nvarchar(5) = NULL
AS

DECLARE @sql nvarchar(max) = '
SELECT *
FROM LogsView
WHERE (CreatedDate >= @FromDate AND CreatedDate <= @ToDate)
  AND (
    IsCritical = 1
    OR (1=1';

IF @SearchText IS NOT NULL
    SET @sql += '
      AND [Text] LIKE ''%'' + @SearchText + ''%''';

IF EXISTS (SELECT 1 FROM @LogTypeIds)
    SET @sql += '
      AND LogTypeId IN (SELECT Id FROM @LogTypeIds)';

IF EXISTS (SELECT 1 FROM @AreaIds)
    SET @sql += '
      AND OperationAreaId IN (SELECT Id FROM @AreaIds)';

IF EXISTS (SELECT 1 FROM @SubTypeIds)
    SET @sql += '
      AND Subtype IN (SELECT Id FROM @SubTypeIds)';

IF EXISTS (SELECT 1 FROM @UnitIds)
    SET @sql += '
      AND Unit IN (SELECT Id FROM @UnitIds)';

SET @sql += '
    )
  )
ORDER BY
  CreatedDate' + IIF(@SortDirection = 'DESC', ' DESC', '');

IF @SortField = 'LogTypeId'
    SET @sql += ',
LogTypeId' + IIF(@SortDirection = 'DESC', ' DESC', '');

PRINT @sql;  -- your friend

EXEC sp_executesql @sql,
  N'@FromDate       datetime2,
    @ToDate         datetime2,
    @SearchText     nvarchar(100),
    @LogTypeIds     Ids READONLY,
    @AreaIds        Ids READONLY,
    @SubTypeIds     Ids READONLY,
    @UnitIds        Ids READONLY',

    @FromDate = @FromDate,
    @ToDate = @ToDate,
    @SearchText = @SearchText,
    @LogTypeIds = @LogTypeIds,
    @AreaIds = @AreaIds,
    @SubTypeIds = @SubTypeIds,
    @UnitIds = @UnitIds
;

It's not clear from your description, but it seems you always want to sort by CreatedDate, and possibly also by LogTypeId depending on the parameter.