that would require you to set up a domain name and use DDNS and trust your registrar, or to just always have your computers at a static IP with no NAT blocking you whatsoever.
I tried Termux and found the application files I wanted to rsync aren't visible in Termux, except maybe by rooting the phone. But I need to use banking and auth apps daily on it, so I assume that isn't an option.
You have to use `termux-setup-storage` to gain access to shared storage. If you're referring to an app's private app data folder, there's no way to access that without root via any app.