Prioritize Vlan

Good evening, I have a question, I have configured a neutral router RB4011 (I have removed the one from my ISP) the issue is that my ISP requires to raise pppoe through a Vlan, everything is correct, but the contracted speed does not arrive correctly, and it tells me I have to put in the Vlan the priority bit, an id, I can’t find in MK where to put that parameter. Thank you very much in advance.

Very good question.
The assigning of the vlan is the easy part assigning the priority bit is what I couldnt do on a zyxel router many moons ago (as I needed a priority bit set on the initial handshake for IPTV).

In IP firewall rules advanced settings I see there are three related potential settings, Ingress Priority, Priority, DSCP (TOS):
'Perhaps this can be used for a WAN to router input chain rule???