The router model you provided may be a bridged device.
If you want to activate LAN2, LAN3 and LAN4 interfaces, please check the settings of your ONT on the OLT side.
The following four commands are usually used:
ont port native-vlan 0 30 eth 1 vlan xxxx priority 0
ont port native-vlan 0 30 eth 2 vlan xxxx priority 0
ont port native-vlan 0 30 eth 3 vlan xxxx priority 0
ont port native-vlan 0 30 eth 4 vlan xxxx priority 0
Thank you!