How to add ipvs rule to nftables?

I want to do the equivalent of

iptables -t nat -A POSTROUTING -m ipvs --vaddr 1.2.3.4 -j MASQUERADE

in nftables. The nftables wiki says ipvs is supported, but

add rule ip nat POSTROUTING ipvs vaddr 1.2.3.4 masquerade

does not work. All other variations I have tried do not work either... When I add the rule using iptables and list all rules using nft, I get

vaddr 1.2.3.4 counter packets 0 bytes 0 masquerade

but using this in "add rule" does not work either.

So what would be the correct syntax to use nft in this case?