TC class addition failed

I have uploaded the new OpenWrt firmware 19.07.4 of my ArcherC6v2(EU) router and trying to add TC classes, but while adding I am getting the following error.
root@OpenWrt:~# tc class add dev ifb0 parent 1:1 classid 1:101 hfsc sc rate 3Mbit ul rate 3Mbit
RTNETLINK answers: No such file or directory

Can anybody help me with this? Am I missing any kernel module?