Is it possible to retrieve sensor data older than 30 days?

This is currently not possible.

Studio, and the historical API is not designed to act as a source for data science, or as a backup, for platform partners. Having access to the last 30 days of data is a convenience that is valuable during installation and to allow backfilling in case of Data Connector issues.

If you are using a platform provider, then please contact them to understand how they handle historical data. Many platform providers save all sensor data forever.

If you are a platform provider, please see the Developer site on multiple guides on how to integrate with different cloud vendors.