I have an Orange Pi Zero with Armbian, and I would like to access the Transmission that I have installed from any other device outside the local network, I know the external ip of the device (I do not understand why it always changes, I would like to get an explanation, and know how to leave it fixed to be able to be). I have added the ports to open in the router (51413 and 9091) but I can not connect, I have the settings.json configured to get any ip: whitelist = 127.0.0.1, . . .
I still can not access externally from my phone (for example) using data, I do not understand much about the subject, I know that I have "iptables" disconnected.
How to know with certainty which ports are open and what steps are missing? Thank you very much
Greetings