[FROG] Questions of bgp vrf configuration

Hi， As said in the frrouting document，Configuration for vrf exported routes must, at a minimum, specify two parameters：RD and RTLIST. Configuration of route leaking between a unicast VRF RIB and the VPN safi RIB of the default VRF is accomplished via commands in the context of a VRF address-family. So, where is the command “rd vpn export AS:NN|IP:nn”, I can’t find it in frrouting, please show me how can I configuration this command, thanks.