blazor with MySql EntityFrameworkCore return output parameter get error

i am using MySql.Data.EntityFrameworkCore with blazor and when i want to get output value total count for pagination from store procedure i get below error

Error: MySql.Data.MySqlClient.MySqlException (0x80004005): OUT or INOUT argument 1 for routine get_articles is not a variable or NEW pseudo-variable in BEFORE trigger

below code is my store procedure

DELIMITER $$
CREATE PROCEDURE get_articles(IN _offset INT, IN _count INT, OUT _total INT)
BEGIN
SELECT SQL_CALC_FOUND_ROWS * 
FROM content c JOIN content_types t 
ON c.content_type = t.id
WHERE t.name = 'article' 
LIMIT _offset, _count;
SET _total = FOUND_ROWS();
END$$
DELIMITER ;

below code is c#

var totalCount = new MySqlParameter()
{
ParameterName = "@TotalCount",
Direction = System.Data.ParameterDirection.Output, 
};

var earningTypes1 = await dbContext.Result.FromSqlRaw(
"CALL get_articles (0,30,@TotalCount)",
totalCount
).AsNoTracking().ToListAsync();

Use CommandType.StoredProcedure instead of explicitly CALLing the stored procedure:

using (var command = new MySqlCommand("get_articles", dbConnection))
{
    command.CommandType = CommandType.StoredProcedure;
    var totalCount = new MySqlParameter()
    {
        ParameterName = "@TotalCount",
        Direction = ParameterDirection.Output, 
    };
    command.Parameters.Add(totalCount);

    using (var reader = await command.ExecuteReaderAsync())
    {
        // build list from results
    }

    // use totalCount.Value...
}

Note that if you're using async DB operations, you'll want to make sure you're using MySqlConnector as your ADO.NET library and Pomelo.EntityFrameworkCore.MySql for EF.Core, as they're the only MySQL libraries that support async I/O.