How modify vxlan default port when deployment rancher 2.6.x

rancher 2.6.5

Configure vxlan port follow by blow link, but it does not work

plugin: canal
canal_iface: eth1
canal_flannel_backend_type: vxlan
# must be 4789 if using Flannel VxLan mode in the cluster with Windows nodes
canal_flannel_backend_port: “8872”

and I can not find guide in doc of new version:

So, anyone know how to modify vxlan default port?