if your ONT/ONU has a 10GB port, you can connect your router (there's really no modem in the "BE7200") to it and get internet service. not all ONT/ONU will support above gigabit connections, so it might just drop to a 1000 Mbps, or not work at all (for this range of devices, it'll probably work). a good CAT6 cable will do 10Gbps for 30m, even 50m.
if your pc has a 10G NIC, just plug it into the "10G" LAN port on your router and you're good to go.
However, TP-Link BE7200 is quite possibly the "Archer BE450". according to specs, it has a 10G WAN port and a 2.5G LAN port. even if the WAN to ONT/ONU port works, check if the 10G NIC on your pc will work at 2.5Gbps, as some will only do 10G/1G. if it's the latter, it'll just sync at 1G.
anyway, madali lang naman subukan. just get a couple of CAT6 cables.