Drupal 8.x

I'm trying to rebuild the Bootstrap 3.3.7 menu to Bootstrap 4.1
In links it is necessary to receive a class active instead of is-active

{% import _self as menus %}

{{ menus.menu_links(items, attributes, 0) }}

{% macro menu_links(items, attributes, menu_level) %}
{% if items %}
{% if menu_level == 0 %}
<ul class="navbar-nav mr-auto">

{% for item in items %}

I have not found the documentation or forum posts helpful for this specific situation, so suggestions would be very appreciated.

I have a bunch of Drupal 8 sites that are subdomains, such as hostingservice.com\website.info

I also have cPanel Add-On domains, such as website.info

For trusted host patterns, which pattern do I use - or do I have to do both?

If hostingservice.com\website.info, how would that be written in the code?

1. hostingservice.com\website.info

2. website.info

Thank you in advance.

...on my D7 sites, anyway.  I'm not sure where things like this should go, but people might watch out for requests like these:

 https://example.com/?q=user%2Fpassword&name%5B%23post_render%5D%5B0%5D=array_map&name%5B%23suffix%5D=eval%28%24_POST%5B23%5D%29%3B%2F%2F&name%5B%23type%5D=markup&name%5B%23markup%5D=assert

Hello,

after an attack on a website I earlier built and managed, I wonder how to secure my own website. I use D8 for a website with no other users than me. There is no interaction, no forms to fill in, just pages. I wonder if such a website can be harmed by attacks as they were possible after the latest Drupal Core Remote Code Execution issue...

As you can read I have no clue about those issues, so I wonder: If I offer no way to post somethng into my database, are there still ways to intrude code when such security issues occur?

Hello.
I want to sell monthly subscription using Drupal 8 .
Is there any way to do that?

there is some toturials for drupal 7 but I couldn't use them for my website.

I tried to use Rules Module but i got unexpected error.

Hello,

today I try tu upgrade my drupal website fromù 8.2 to 8.5

I delete folder core and vendor (and top level directory), update new file with FTP. Then I try to launch update.php, but I have an error :

Fatal error: Interface 'Drupal\Core\ParamConverter\ParamConverterInterface' not found in /datas/var/www/htdocs/core/lib/Drupal/Core/ProxyClass/ParamConverter/MenuLinkPluginConverter.php on line 15

somebody can help me for this problem ?

Thanks for your help