With the release of Envoy app 2.0.1, the software has added an option to export labels and tags in BIP-329 format. I believe that only exporting works as there doesn't seem to be an import feature.
Here is how you can do that:
* Foundation Devices and Envoy App
Supports exporting labels: Yes
Envoy supports exporting of labels and tags as .json files in BIP-329 format.
How to export labels using the Envoy app:
1. From the Account selection, click on the two horizontal lines on the top left.
2. Click "Backups."
3. Click "Advanced Backups."
4. Select "Export Tags & Labels (BIP-329)" and select a location where you want to save the file.
5. Click "Save."