rekey needed for private storage directory on (same) older device

because of an init error that started occurring on app launch few months ago, I needed to reinstall, luckily I copied the keybase app installation folder (and I think I got the keys to do this manually and remove old device).
the emails from keybase instruct to just launch the app on the other older PC device (previous installation) so it can auto rekey.
[error message I was getting on launch](https://i.imgur.com/LoIV5Js.png)
How can I do this manually with the CLI? how do I use the files of previous installation (which I was signed in with the command line and was successful in adding a device) to sign in now to use the CLI? if the new installation is a newer version will it work nonetheless?

Start with the app-launch init error shown in the linked screenshot and the copied previous installation folder. Investigate how the prior CLI-signed-in installation and its files could be used for rekeying, and whether a newer installation can consume them. Done means documenting a reliable manual CLI recovery procedure or identifying the missing information needed.

Written by the indexing model from the issue text.