Execute async non selectable stored procedure in EF Core 2.1

I'm trying to execute async non selectable stored procedure in EF Core 2.1.

  return Ok(
              await db.Set()
              .FromSql($"EXECUTE PROCEDURE MY_PROC({id})")
              .ToListAsync());

Error:

The type arguments for method 'DbContext.Set()' cannot be inferred from the usage. Try specifying the type arguments explicitly

I also tried:

return Ok(
             await db.MYDB
              .FromSql($"EXECUTE PROCEDURE MY_PROC({id})")              
             .ToListAsync());

Error:

500 (Internal Server Error) in console

Then I tried creating a static method:

public static async Task ExecSqlNonQuery(Entities db, string sql)
{
     using (var com = db.Database.GetDbConnection().CreateCommand())
     {
         com.CommandText = sql;
         com.CommandType = CommandType.StoredProcedure;
         db.Database.OpenConnection();
         await com.ExecuteNonQueryAsync();
     };
}
....
return Ok( await ExecSqlNonQuery(db,$"EXECUTE PROCEDURE MY_PROC({id})");   

but with this code, I get:

Argument 1: cannot convert from 'void' to 'object'

only works on non async and old-fashioned way:

public static  bool ExecSqlNonQuery(Entities db, string sql)
{
    try
    {
        using (var com = db.Database.GetDbConnection().CreateCommand())
        {
            com.CommandText = sql;
            com.CommandType = CommandType.StoredProcedure;

            db.Database.OpenConnection();
            com.ExecuteNonQuery();

            return true;
        };
    }
    catch (Exception)
    {
        return false;
    }
}
......
return Ok(ExecSqlNonQuery(db, $"EXECUTE PROCEDURE MY_PROC({id})"););

Any help? Thanks