First we need to setup the the Target port, i.e., the port we want to send our mirrored traffic to. Go to Switch -> Settings -> Select the Switch -> Mirror Target. Select the port you want to mirror to.

Next, we need to configure which port(s) we want to use as source ports.

Go to Switch -> Ports -> Select the Port

Select Mirror Ingress and/or Mirror Egress and apply.

That is it. All traffic on your configured ports will now mirror to the target port.