How can I set up automatic translation of pages into another language if the page is not translated manually?

Question

Google translate

Good afternoon!
There is a real estate site on Wordpress, with a very large number of "houses" uploaded from a third-party service, as well as information pages (how to get a loan, what you need to know when choosing a house, etc.).
For information pages, there are pre-ordered translations from English. in Russian language.

The task is as follows: for information pages, the translation should be manual, and for all the rest, automatic.

Can you please tell me how to implement something like this?