Dave,
Wappler’s part of the whole process is to build the front and back end for your app, then connect them togehter, then build them together as an app package (apk/ipa) and if you wish - to emulate it on your connected device or emulator (if you have one installed).
Then, when you go and publish your app, you usually check the App Stores’ guides on signing and publishing.
More, you can check every platform’s docs directly from within Wappler:
As for server security settings - how can we guess your server runs some weird security settings, that probably nobody else uses? I remember this being an issue only on your server even with simple server connect actions. It’s not possible to guess all the security settings the user may or may not have set up on his server.