The history (audio) is contained in / Zello / history in the corresponding profile (32-bit subdirectory) in the data, db and db-journal files. Copy them to another device in the desired profile (not necessarily the same as the original one) and you can easily watch / listen. Photos are stored in the / images subdirectory
There you only need to make sure that on the second device the size of the history (voice messages) is not less than on the original one.
I found both history files on the android and on the PC, they are not heard on another device, if copied to the appropriate folder, i.e. in the recents section do not appear.