Notifications Markup not working as expected?

   Notification::make()
                        ->title('Summer Student: ' . $this->student_name)
                        ->icon('heroicon-o-tag')
                        ->body(Str::markdown('**School:** ' . $this->schoolname . ' **Grade Level:**' . $this->grade_level . ' '))
                        ->iconColor('danger')
                        ->color('danger')
                        ->persistent()
                        ->send();