Activated viber on another phone. Is it possible to get history from the old one?

Question

Backup

I bought a new phone, moved the SIM card from the old phone, installed viber and activated it on the new phone with the old number.
Then I realized that the whole history of correspondence remained on the old one, and I would like to keep it. I put the SIM back in, went to viber. He shows me the screen "welcome to viber". I’m afraid to press anything further - suddenly the history is still stored somewhere in the files (it’s not deleted immediately on a signal from another phone, even if I didn’t turn on the application), and I’ll delete it with my actions.
Tried to go the other way. I installed the Backuptrans Android Ios Viber backup program on the computer. Enabled developer mode on smart. Connected smart to the computer. He automatically installed the Backuptrans application on the smart phone and issued a request to allow the viber to be downgraded in order to get the database out of it. At the same time, it is written that during the downgrade the database will remain untouched, but it is immediately written that it is recommended to backup messages directly using viber before downgrading.
The dilemma is which is safer? Try to re-activate the viber (if you knew that this would not delete the history) or downgrade the viber using Backuptrans?
Maybe there are other options?