How to debug in Filament

CheckboxList::make('subject_id')
                        ->relationship('subjects', 'name')
                        ->label('Subjects')
                        ->options(function (callable $get) {
                            $patternId = $get('pattern_id');
                            if (!$patternId) return [];
                            return Subject::query()
                                ->where('pattern_id', $patternId)
                                ->pluck('name', 'id');
                        })
                        ->columns(2)
                        ->disabled(fn($record) => filled($record))
                        ->dehydrated(false) // persisted in Pages using afterCreate/afterSave
                        ->helperText('Selections are saved as StudentClassSubjectMapping rows.')

//fillables ...

  //relations
    public function subjects()
    {
        return $this->belongsToMany(
            \App\Models\Subject::class,
            'student_class_subject_mappings', // pivot table
            'student_class_id',               // FK to this model
            'subject_id'                      // FK to subjects
        )->withTimestamps();                  // remove if your pivot doesn't have timestamps
    }