You can use the egress tagging functionality to add a VLAN tag to the packet transmitted from the tool port.
This feature should only be configured on Tool ports and not supported on EC old platforms — (AS5812, AS7712)
pbnoscli# configure terminal
pbnoscli(config)# interface ethernet Ethernet4/1
pbnoscli(config-if)# egress-
egress-tagging Add egress tagging
pbnoscli(config-if)# egress-tagging enable
pbnoscli(config-if)#
pbnoscli# show interface npb Ethernet4/1
===================================
Interface : Ethernet4/1
===================================
Type : tool
Mode : vlan-aware
Ingress-vlan : 6
Egress-tagging : enable
Loopback-mode : disable
pbnoscli#