If you have an older version installed, IPS is not going to FORCE you to upgrade. They may not be able to provide support if you’re not running the latest version, but as long as things are just working they don’t require it.
With that said, they don’t provide old random versions to download and install. So you would not be able to download 4.2.x or 4.4.x and install it simply because you want to run an older version. (You would not want to anyway due to several security fixes that are included in subsequent releases.)
Randy Calvert's post in www was marked as the answer
Inside of your conf_global.php will be:
'base_url' => 'https://www.site.ru/',
Change this to:
'base_url' => 'https://site.ru/',
Basically just remove the www reference. 🙂
My guess is you’re running into an issue with content security policies which prevents your site from being embedded into third party sites
Search the admin CP for:
Allow community to be embedded in an iframe
You might need to change from the default X-Frames-Options which allows content to be linked from just your domain to a custom Content Security Policy.
You can Google how to generate a custom CSP header that you can paste into that section when you choose the option.