Parsing Vk Page without API?

Question

Python

How can I parse all content of messages in vk.com/al_im.php without using vk api.
The problem is that all messages from users are not loaded on the page, and in google chrome, in order to load them, you need to scroll the page below, sending a certain POST request, and the request itself is encrypted!
There was a similar topic on the toaster How now to get a link to mp3 when parsing vk.com (Vkontakte)? , for parsing audio . The method that is described there for encryption and decryption will also be relevant for POST requests - al_im? Or does it need to be taken apart separately?