Does anyone know how to locally access a CALIX ONT; serial console maybe; the Ethernet appears to be disabled and I need to get into it to enable

There is a local connection between two buildings; NO ISP; it appears that the Ethernet interfaces are disabled(no link lights); I would like to console in but have no clue how; the other end is connected and Ethernet works; maybe I can go in through the IP of that one and then to the fiber interface via ip on the other one; have no clue where to start and the manuals talk about all this software with no simple logical way of how to connect or where to get the software outside of logging in through their system ; this is an isolated system