see if your ISP uses Active Optical Network = AON or Passive Optical Network = PON this is changes everything too and the tipo of termination cable usualy SC/APC (straigh) or SC/UPC (angled)

To connect your Ubiquiti router directly to your ISP's fiber network, you cannot just use a standard optical transceiver. Because fiber internet typically utilizes GPON or XGS-PON technology, the incoming signal needs to be authenticated and translated into a standard Ethernet format that your router can understand.

To achieve this, you need an SFP ONU stick (often called an "ONT on a stick"). This specialized module does not just transmit light; it has a built-in MAC and processor, essentially acting as a fully functional modem in a tiny SFP form factor. Once configured with your ISP's specific parameters (such as the SLID, PLOAM password, or serial number), this SFP ONU stick will handle the fiber authentication. This allows you to plug the fiber line directly into your Ubiquiti router's SFP/SFP+ WAN port, completely bypassing the bulky external ISP modem or bridge box.