Want to display a chart using a query on my laravel php setup

Question

So I need to show a pie chart, and I want to use this query

SELECT employees.id,employees.first_name, (SELECT SUM(training_hours.Hours) TotalTrainingHours) as TotalTrainingHours, (employees.TrainingHoursRequired - (SELECT SUM(training_hours.Hours) TotalTrainingHours)) as TrainingHoursRemaining FROM employees INNER JOIN training_hours on training_hours.employee_id = employees.id

however on laravel it shows this error

Call to undefined method Illuminate\Database\Query\Builder::innerJoin()

on my website controller for the query function i am using this code

function index()
    {
        $result=DB::table("employees")
        ->innerJoin("training_hours", function($join){
            $join->on("training_hours.employee_id", "=", "employees.id");
        })
        ->select("employees.id", "employees.first_name", "(select sum(training_hours.hours) totaltraininghours) as totaltraininghours", "(employees.traininghoursrequired - (select sum(training_hours.hours) totaltraininghours)) as traininghoursremaining")
        ->get();
        dd($result);

What should I do here?

I am using a google visualization pie chart.