When can we export with API level 34?

[Taifun]

you already can use the test server now, see the announcement

Technical Preview: Android SDK 34 Update

Hello everyone, ai2-test.appinventor.mit.edu has been updated for the Android SDK 34 Google Play requirement. Starting August 31, all apps deployed to the Google Play Store, which includes App Inventor and all apps built with App Inventor, will be required to target SDK 34. Every update brings new changes to Android's APIs that can break apps and/or extensions. You can read more about breaking changes here. This will be the next major App Inventor update once nb197 with the new UI is deployed. …

Taifun