We are moving into a new build home this month and we have discovered that there is an OTN (Optical Network Terminal) in the cupboard upstairs.
In addition to this we have Ethernet ports around the home in various locations,
How would we set up our BT hub with the OTN?
You can either connect the BT Hub to the ONT in the cupboard and then connect up to three or four Ethernet cables to the ports to provide wired access to other rooms OR you can connect one Ethernet cable to one port and put the BT Hub in the room connected to that port - this will give you better wireless compared with the cupboard but you will only have wired internet in that room.
You plug the BT Hub WAN port into the ONT and the Ethernet cables go from the yellow Hub ports to the wall ports.
Nothing comes with the hub. You have an ONT, a Hub and developer provided Ethernet cabling. You just need to connect it all together as shown in @pippincp 's diagrams.
You don't need an instruction manual, the diagram shows how to connect things together.
Just connect the ONT to the WAN port of the Hub and then connect the LAN ports to the Ethernet sockets. Plugging your device into the Ethernet socket at the distant location is then just like plugging into the Hub.
If you want to site the Hub elsewhere to give better wifi coverage, you will forego being able to connect Ethernet devices in locations other than where the Hub is sited. If you decide to do that, just connect the ONT to the Ethernet patch panel port that goes to your chosen room and then connect the Hub WAN port at the distant location to the Ethernet socket.