There are a few ways that you can access the router remotely. If you are using port forwarding rules to reach the BMS system and are using port 80 to access it, then you can change the port that you would use to access the router remotely.
If you do not have remote access to the router, connect a wired cable to the LAN port and sign into the router then navigate to SYSTEMS-ADMINISTRSTION then navigate to the WEBUI section of the page, enable HTTP and/or HTTPS access and change the port number to a number of your choosing such as 8080, click SAVE and APPLY.
You can then try to access the WEBUI using the Public IP with the port. Example 18.104.22.168:8080
You can also reach the router through RMS CONNECT. This features is offered by Teltonika to the Customer who has Teltonika routers or gateways. It allows remote access to our routers and gateways and It allows users to control and access third party RUT240 LAN devices such as cameras, PC, Industrial PLC etc. It supports RDP, SSH, VNC, HTTP & HTTPS. More information can be found here:
Another alternative is you can also setup a VPN connection and access the BMS system remotely via VPN connection. RUT240 supports various VPN technologies: