Restore Theme to WordPress (Twig Template Engine)

Colleagues
the WordPress site stopped working and the theme flew off on it. The site was restored, but we cannot restore the theme. You need knowledge of the Twig templating engine.

Who knows how to work in it? Can you please respond?

Now for more details: the situation is as follows. There is a website that was launched in 2015, it is already morally outdated (both in design and technically). For example, the theme is written for php 5.5, it does not adapt, because custom.

But I dont have the task of updating the site. Its not a priority for me now. I just need to restore as it was.

Heres what happened. This fall, the site suddenly stopped working. I didnt touch anything at all, the hosting says it didnt change anything either. What happened is unclear.

And the site flew so that even the admin panel stopped working. Again, I didnt touch anything at all.

One technician has successfully restored the admin panel, but he doesnt know twig, and cant restore the theme.

The task is as follows: to restore the topic as it was. Thats it. Can you do it? What do you need for this?

Ready to answer any questions

Sincerely,
Vadim