Converting to Drupal

Im passing a variable '#options' => $subscriber_options, as an option.

Hello! In the early 2004 I've started one blog site on Drupal and it become very popular, so partner come, converted it to ASP and later leave. Now I have it in ASP version. I am trying to convert it back to Drupal and I am making configurations before the migration. I've stuck in one problem:

Hi Guys, 

I'm converting my Drupal 7 site to Drupal 8 and in Drupal 7 I'm using sessions like this:

$_SESSION['ccs']['hpbx']['voicemails']['subscriber_id']

How can I do this in Drupal 8 ?

Please help. 

Thanks in advance. 

This is my twig file of a form where im adding some html, but im not getting that <form class="hpbx-popup-form> tag and this class is necessary as its mentioned in js , so due to this my Set button is not working.

<div id="timeslot-popup" class="hpbx-popup">

<div class="hpbx-popup-content">

<h4 class="hpbx-popup-title">Add a time slot</h4>

Hi Guys, 

I'm converting my D7 website to D8 and in D7 js file I'm calling a ajax request and url is: 

url:  Drupal.settings.basePath + Drupal.settings.pathPrefix +  'system/ajax'

And I have already converted this line as:

url:  drupalSettings.path.baseUrl + drupalSettings.path.pathPrefix + 'system/ajax'

But it is showing 404 not found on the console.

Hi Guys, 

I'm converting my Drupal 7 project to Drupal 8 and in Drupal 7 we are using Drupal.settings.basePath and basePath is set in drupal_add_js function which is deprecated in Drupal 8. 

So, How can I use this basePath in Drupal 8 js ?