Backup / Restore page is under Assets > Settings > Backup / Restore
You can export your Assets and Inventory Plugin entire data to JSON file as well as import from JSON. This a complete backup and restore process.
This operation backup and restore your assets, asset types, and attributes.
JSON Data import will wipe all existing Assets And Inventory Plugin content, including the Asset custom fields' value for the JIRA issues. It is strongly recommended that you backup your database first!