Set MTU=9000 via UCR


I would like to set the MTU for the LAN interface to 9000. With UCS I may/should not edit the file (/etc/network/interface) but set the value via UCR. The LAN interface:

ens18: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 5a:65:eb:28:35:be brd ff:ff:ff:ff:ff:ff
    inet 192.168.xx.5/24 brd scope global ens18
       valid_lft forever preferred_lft forever
    inet6 fe80::5865:ebff:fe28:35be/64 scope link 
       valid_lft forever preferred_lft forever

What would the call be now. Like this:

ucr set interfaces/ens18/options/mtu=9000

with best

coorect is:
ucr set interfaces/ens18/mtu=9000