There is development ongoing to lock the database to prevent corruption during backups but it is not available yet.
Your best bet would be to use the MariaDB addon instead of the default SQLite DB. This can be stopped while you make a backup. Failing that…
Your second best bet would be to make a full backup of home assistant. Then stop home assistant and copy the database file either by using SSH or the Samba addons. config/home-assistant_v2.db
Restore the backup to the new system then stop Home Assistant and copy across the database file. Then start home assistant.