OpenHAB remote access via Android/iOS (not cloud)

Hello community.
I have a question about remote access to OpenHAB server (RPI3) via Android/iOS app without using cloud (just for temprotaty and for testing). I execute port forwarding to :8080 (I know it is to dangerous, but as was mentioned above I am going to do that only for testing purposes and for temporary). I know that I can type in local URL field next structure http://UniqIP:MyPort and then connect remotely as locally. But in this case I should be connected to any wifi network. If not, I will not connect. So, it seems to me, that I must fill remote URL field with correct data. I have HTTP connection type, Unique IP address and Port number (that I forwarded to port 8080). But I don’t know what should I type at remote URL field (I try a lot of combinations and nothing is correct). Do somebody have exprirence with it and can share ?