transfer viber chat history to iphone problem

transfer viber chat history to iphone, is there a way to restore viber history from android to iphone, why those questions are not solved. if someone has important messages and if they want to continue where they left off, to save important messages, that is not enabled, is it up to viber or the developers who made it that you simply have to lose everything. why isn't there a solution or the possibility to choose the cloud where the messages will be stored so that they can be returned more easily, and something else is funny, that on the iPhone you cannot change the ringtone for Viber, and on Android you choose what you want, here is the only you can change the notifications,,,these are one of the problems that are not solved