Bringing things in
The phone app
A FlutterFlow export, in its own place beside the website.
A phone app from FlutterFlow has its own place in a project, beside the website.
Bringing one in
Export the code from FlutterFlow as a zip, and add it with + on New project, or Apps › Mobile › + New in a project you have. FlexOS spots it's a FlutterFlow app and puts it in the phone app's own folder; its keys go to the Vault. It shows under Apps › Mobile.
Putting it in the App Store and Google Play from FlexOS is not there yet.
Where next
Still stuck? Ask Flexi in your project, or ask a flexpert.