Not a direct solution, but I found an interesting feature named SSH console. It won’t enable you to access your NAS directly but instead open SSH in the browser to access it remotely. Then you can somehow put some file on another cloud to access it from host machine. I know it’s not what you want but you know, doesn’t need any software other than a browser this way ;)
If you want to learn to secure your network, try using snort. It’s a popular intrusion preventing system.
Another interesting thing is to host a Wireguard VPN server. You can access your selfhosted services from outside of your house by connecting to the VPN.
In my opinion, learning to setup these kind of things is the most interesting and beneficial way to learn things around them.