Connect x86 router to ISP Router in bridge mode

Installing and Using OpenWrt
5

I followed these steps of this user because we have the same ISP router brand:

https://forum.openwrt.org/t/novice-trying-to-understand-bridging-and-vlans-for-correct-configuration/157314

As far as I understand my ISP router uses VLANs for internet, voip and iptv. But as I said before I didn't have to tweak these settings on my old Asus router...