Multicast traffic / dedicated port for TV BOX

Hello,
I am new in microtik and would like to connect my TV internet BOX behing the mikrotic router, and this seems quite difficult for a beginner.
What is working today:

To avoid two cables, would like to use setting below (yes I already tested to connect the TV box on the network 192.168.88.0 and it does not work). IGMP snooping should also be implement to only forward the multicast flow to ether5.

I started with the HOME AP dual and implement bridgetv and vlan…but do not know how to have the ether5 being configured “as the trunk extension”… Any help would be nice!
thks