It's planned via https://github.com/LemmyNet/lemmy/issues/2631 once lemmy supports.
Without that, there's two ways to do this with major drawbacks:
- Background tasks (android supported-ish with iOS support only with app open): Apps like Thunder are doing partial implementations by essentially polling the lemmy server in the background. I don't think this is very neighborly because it puts a strain on Lemmy instances with the polling per account every 15 mins. It also consumes more battery. And is not consistent depending on Android device manufacturer.
- Storing JWTs on a server: Some apps do this, but this is a nonstarter for me due to security/liability reasons
So IDK. Right now I feel pressure to do this because other apps support but the ways they are accomplishing this are pretty questionable.