Unlike Droplet, App Platform apps run in ephemeral containers. The console is available for debugging issues, but we STRONGLY recommend against modifying files in the container as they’ll be discarded they next the app is deployed. New deployments are rolled out (destroying any modified files) when changes are pushed to the git repository, settings changes are made to the app, or when the app needs to be rescheduled or updated for maintenance.
The tools included in the container image vary based upon the language and frameworks detected for your source code. If you need additional utilities like editors you might consider using a Dockerfile based build.
Hope this helps!