Generally, the data should be in the Eufy app when you log in to the same Eufy account on the new phone as long as the data is not deleted. Please follow the steps below to get the previous data:

Uninstall the Eufy app then reinstall it >> open the app >> after the app gets the previous data, step on the smart scale to weigh yourself.

During that process, if you step on the smart scale before the app gets the historical data, the previous data will not show in your app.

If it fails to restore the data, please contact us  for further assistance