Not the best way but :

1. Let a computer online 24/7 on the same network as your antminer. (let's say it's computer A)
2. Install teamviewer on it.
3. Install teamviewer on the computer / smartphone you want to use for monitoring.

Take distant control of the computer in your network (computer A)
Open a web browser (on computer A) and type the IP of your antminer in it.

Understood ?

There also are better way using VPN boxes etc... but it's maybe a bit more complicated.