In phone settings, go to Chats > Chat Backups > Create Backup.
Signal will generate a 30-digit key. Be sure to save it offline, otherwise you won't be able to decrypt.
Transfer the backup file to a new device and enter the key to restore.
For AI services, exported JSON files may contain your private information (such as phone numbers, API keys). Please ensure proper sanitization before uploading to third-party analysis tools.