[nft 0.9.0] MSS clamping producing Error: Could not process rule: No such file or directory

[ѽ҉ᶬḳ℠ <vtol@xxxxxxx>]

kernel 4.14.131 with installed modules:
nftables, kmod-nft-arp, kmod-nft-bridge, kmod-nft-core, kmod-nft-fib,
kmod-nft-nat, kmod-nft-nat6, kmod-nft-netdev, kmod-nft-offload, libnftnl

not installed: libxtables-nft, nft-qos
__________


table ip filter {
    chain input {
        type filter hook input priority 0;
    }
    chain forward {
        type filter hook forward priority 0;
    }
    chain output {
        type filter hook output priority 0;
    }
}
____________

Either

# nft add rule ip filter forward oifname pppoe-wan tcp flags syn tcp
option maxseg size set rt mtu
# nft add rule ip filter forward oifname ppp0 tcp flags syn tcp option
maxseg size set 1452

is producing > Error: Could not process rule: No such file or directory


What is missing or what I am missing?