Upsert SQL query

I am looking for some advice how to optimize a couple of SQL stored procedures. With the 1st query I am doing insert, and with the 2nd one I am doing update, if the data exists.

What I want to do is merge both stored procedures in one, where the query will check if the data exists than update, else insert a new row.

Here is what I have at this time:

update SP:

ALTER PROCEDURE [dbo].[UpdateStep1](@UserId nvarchar(50), @First_Name nvarchar(50), @Last_Name nvarchar(50),
                             @TitlePosition nvarchar(30))                                                   
AS
BEGIN
UPDATE Company_Information
SET First_Name = @First_Name,
    Last_Name = @Last_Name,
    Title_Position=@TitlePosition,  
    WHERE UserId = @UserId
    END

insert SP:

ALTER PROCEDURE [dbo].[InsertStep1](@UserId nvarchar(50), @First_Name nvarchar(50), @Last_Name nvarchar(50),
                             @TitlePosition nvarchar(30))
                            
AS
BEGIN
    INSERT INTO Company_Information(UserId,
                                    First_Name,
                                    Last_Name,
                                    Title_Position)
                                    
                                    VALUES
                                    (@UserId,
                                    @First_Name,
                                    @Last_Name,
                                    @TitlePosition)
END

So, I would like to merge both SP in one, and the SP to check if there is already data for that UserId than update, else insert a new row.