Hi friend.
You can refer to the following configuration example:
Configuration Case Description: LAN1 is the uplink port. TrunkVLAN ID is 500.
1. The PC is directly connected to the LAN port of the device and accesses the device through 192.168.18.1.

2. Configure the uplink port and click Apply.

3. Configure other LAN ports(except the configured uplink port) and click Apply.

4. Configure the WAN and bind the LAN and WAN. The trunk VLAN is also configured on this page.

I hope I can help you!