There are many places you can get in depth tutorials for port forwarding. Portforward.com is one. If you read past all of the sales pitches, accessing your router management page should give you the settings needed.
Loctus states static IP's and port forwarding.
Don't confuse your public IP. The IP address your ISP assigns to your cable modem, ONT if you have fiber.
For your private (in your home) IP address.
All of your devices on your home network will have a private IP assigned to them. If you look in the mio network settings I believe you should see that the IP address is set to DHCP. If you haven't changed it to static IP.
This means that your router will "hand out" a local IP address to it. Let's say it happens to be 192.168.0.105
It is dynamic. The next time you reboot the router, restart the receiver. The local IP could change. It might be
192.168.0.86. Dynamic meaning things can change.
If you edit files on the mio. And you have Filezilla set to connect to it using 192.168.0.105
Mentioned above. If it gets a new local IP of 192.168.0.86 from the router. "Connection Error". Yeah?
Looking for shared files on different pc's in your home over your network. Or recorded movies on the mio to play on another device. It can become a bear. Right? Kind of like some pranksters changing mailbox numbers up and down the block over night. You need some Epoxy to glue the house number fast so that Dominoes can get that pizza to you.
They know that you live on a certain street (your public IP address....maybe 210.137.103.118) but will be banging on doors up and down the street to find you. Make sense?
Your "Epoxy" is in the form of setting up a static IP on the mio. 2 ways. In your router and/or in the mio.
In my situation my mio IP is fixed at 192.168.5.205. I can control that. My public IP, I can't.
Businesses can buy static IP's. Like here on Satguys. If you can find the public IP of it. You can type the address in the form of numbers in the address bar.
https://144.126.131.153 will get you here.
(That's exactly how a girl at work bypassed company wifi access to Facebook. She resolved the IP to numbers and wa-la.....Bob's your uncle....but your mom knows better).
If you forward a port on the mio to the public Internet. You....or a hacker plinking around for tid-bits....could get into it and go to town. No forwarded ports. If your router is doing its job. Will show nothing on your home network at all.
That's why setting up a VPN server on your router is the best idea for accessing your home network outside your home. Extremely secure. You can generate new secure keys and user name/passwords on a whim.
As far as I know. Wireguard being the 'best' is not exactly user friendly. I don't think there is a GUI for it. Maybe.
Openvpn as you see in my previous post is a breeze (almost) to setup and use.
But Google is your friend for in depth tutorials really.