Convert SQL stored procedure to Linq

I created the following stored procedure:

PROCEDURE [dbo].[LeadScoring_CountClosedActions]
    (@UserId INT,
	 @StartDate INT,
	 @EndDate INT)
AS
BEGIN
    SET NOCOUNT ON

    SELECT TOP 1 
        COUNT(l.Extra) OVER () AS TotalRecords
	FROM 
        [dbo].[LeadScoringActions] AS a
	INNER JOIN 
        [dbo].[LeadScoringLeads] AS l ON a.LeadId = l.LeadId
	WHERE 
        a.AssignedToUserId = @UserId 
		AND a.DateCompleted > DATEADD(DAY, @StartDate, GETDATE())
		AND a.DateCompleted <= DATEADD(DAY, @EndDate, GETDATE())
		AND a.ActionResultType != 'System Closed'
		AND l.Extra IS NOT NULL
	GROUP BY 
        l.Extra
END

And I was trying to execute it with the following in EF Core:

var count = await _context.Database.ExecuteSqlRawAsync($"exec LeadScoring_CountClosedActions @UserId={userId}, @StartDate={request.StartDate}, @EndDate={request.EndDate}");

But it was always returning -1 so I had a look around and it would seem I should convert the stored procedure to Linq (see one of the comments on this question)

I was wondering how I would do that - I know how to do the general bits:

var count = await _context
                    .Actions
                    .Include(a => a.Lead)
                    .CountAsync(a => a.ActionResultType != LeadScoringConstants.SystemClosed &&
                                     a.DateCompleted > DateTime.Today.AddDays(request.StartDate) &&
                                     a.DateCompleted <= DateTime.Today.AddDays(request.EndDate) &&
                                     a.AssignedToUserId == userId &&
                                     a.Lead.Extra != null);

But I'm not sure how to do the GROUP BY - in the linq, it would be grouped by a.Lead.Extra or if it's possible to do a COUNT OVER?

Is it better to do it as linq or is there a way to execute the stored procedure and get the correct result?

In the end I solved it using linq by getting the matching actions from the db then I got the distinct extra properties from the results and counted them:

var actions = await _context
                .Actions
                    .Include(a => a.Lead)
                .Where(a =>
                    a.ActionResultType != LeadScoringConstants.SystemClosed &&
                    a.DateCompleted > DateTime.Today.AddDays(request.StartDate) &&
                    a.DateCompleted <= DateTime.Today.AddDays(request.EndDate) &&
                    a.AssignedToUserId == userId &&
                    a.Lead.Extra != null)
                .ToListAsync();

var projectIds = actions.Select(a => a.Lead.Extra).Distinct().Count();

As per comments, I can change this to be done in linq:

var count = await _context
    .Actions
    .Where(a =>
        a.ActionResultType != LeadScoringConstants.SystemClosed &&
        a.DateCompleted > DateTime.Today.AddDays(request.StartDate) &&
        a.DateCompleted <= DateTime.Today.AddDays(request.EndDate) &&
        a.AssignedToUserId == userId &&
        a.Lead.Extra != null)
    .Select(a => new { a.Lead.Extra, a.DateCompleted })
    .Distinct()
    .CountAsync();