The import-rib evpn srv6 ip-prefix command enables the VPNv6 address family to import routes from the EVPN address family.
The undo import-rib evpn srv6 ip-prefix command disables the VPNv6 address family from importing routes from the BGP-EVPN address family.
By default, the VPNv6 address family is disabled from importing routes from the EVPN address family.