I followed this gist (https://gist.github.com/leabdalla/5999421) to achieve the goal, but because Sentry 2 uses different approach to implement in FuelPHP than Laravel it needed some additional code. So here is a solution for that.
Note that this is not perfect solution, and it could break when we do composer update, because it depends on current Sentry version.
You will need to create this file structure: