Google Android to Ghost Phone
If you are looking to migrate FROM a Google Android device to the Ghost Phone (or any de-googled NON iPhone device), on both your new and old device install the app "SMS Backup & Restore". On your new device you will find this within the Aurora App Store and not in the F-Droid app store. Run and follow the simple prompts on both devices. Should take you no more than 5-10 minutes depending on how many calls and text messages you are looking to migrate.

For a video tutorial, check out THIS LINK

iPhone to Ghost Phone
Unfortunately Apple has made it a bit more complicated for customers to leave their ecosystem and, as such, if you are looking to migrate your text and phone logs FROM an iPhone to the Ghost Phone (or any de-googled NON iPhone device), the process is a bit more complicated.

Not FREE but simple way to do the transfer = https://mobiletrans.wondershare.com/phone-to-phone-transfer.html
@ $30 for Windows version
@ $45 for iOS version
Process should take 5-10 mintues based on how much data you are looking to transfer.