You can configure additional paths (for both IPv4 and IPv6) when you create or update a BGP peer.
efa tenant service bgp peer create --name <bgp-peer-name> --tenant <tenant-name> 
        --ipv6-uc-nbr-add-path-capability <device-ip,vrf-name:neighbor-ip,
               {send | receive | both}>
        --ipv6-uc-nbr-add-path-advertise-all <device-ip,vrf-name:neighbor-ip,
               {true | false}>
        --ipv6-uc-nbr-add-path-advertise-group-best <device-ip,vrf-name:neighbor-ip,
               {true | false}>
        --ipv6-uc-nbr-add-path-advertise-best <device-ip,vrf-name:neighbor-ip,
               2-16>
                efa tenant service bgp peer update --name <bgp-peer-name> --tenant <tenant-name> 
        --ipv4-uc-nbr-add-path-capability <device-ip,vrf-name:neighbor-ip,
               {send | receive | both}>
        --ipv4-uc-nbr-add-path-advertise-all <device-ip,vrf-name:neighbor-ip,
               {true | false}>
        --ipv4-uc-nbr-add-path-advertise-group-best <device-ip,vrf-name:neighbor-ip,
               {true | false}>
        --ipv4-uc-nbr-add-path-advertise-best <device-ip,vrf-name:neighbor-ip,
               2-16>
                | Rack1-Device1# show running-config router bgp router bgp local-as 4200000000 capability as4-enable fast-external-fallover neighbor 10.20.20.4 remote-as 4200000000 neighbor 10.20.20.4 next-hop-self address-family ipv4 unicast network 172.31.254.46/32 network 172.31.254.123/32 maximum-paths 8 graceful-restart ! address-family ipv4 unicast vrf ten1vrf1 additional-paths select all redistribute connected neighbor 10.20.30.40 remote-as 50000 neighbor 10.20.30.40 additional-paths send receive neighbor 10.20.30.40 additional-paths advertise best 10 group-best all neighbor 10.20.30.40 bfd neighbor 10.20.30.50 remote-as 50000 neighbor 10.20.30.50 additional-paths send neighbor 10.20.30.50 additional-paths advertise best 8 group-best all neighbor 10.20.30.50 bfd maximum-paths 8 ! address-family ipv6 unicast ! address-family ipv6 unicast vrf ten1vrf1 redistribute connected maximum-paths 8 ! address-family l2vpn evpn graceful-restart ! ! | Rack1-Device2# show running-config router bgp router bgp local-as 4200000000 capability as4-enable fast-external-fallover neighbor 10.20.20.5 remote-as 4200000000 neighbor 10.20.20.5 next-hop-self address-family ipv4 unicast network 172.31.254.46/32 network 172.31.254.176/32 maximum-paths 8 graceful-restart ! address-family ipv4 unicast vrf ten1vrf1 additional-paths select all redistribute connected neighbor 10.20.30.40 remote-as 50000 neighbor 10.20.30.40 additional-paths send receive neighbor 10.20.30.40 additional-paths advertise best 5 neighbor 10.20.30.40 bfd neighbor 10.20.30.50 remote-as 50000 neighbor 10.20.30.50 additional-paths receive neighbor 10.20.30.50 additional-paths advertise best 4 neighbor 10.20.30.50 bfd maximum-paths 8 ! address-family ipv6 unicast ! address-family ipv6 unicast vrf ten1vrf1 redistribute connected maximum-paths 8 ! address-family l2vpn evpn graceful-restart ! ! | 
For syntax and command examples, see the ExtremeCloud Orchestrator Command Reference, 3.6.0
efa tenant service bgp peer create --name ten1bgppeer1 --tenant ten1 --ipv4-uc-nbr 10.20.246.15,ten1vrf1:10.20.30.40,50000 --ipv4-uc-nbr-bfd 10.20.246.15,ten1vrf1:10.20.30.40,true --ipv4-uc-nbr-add-path-capability 10.20.246.15,ten1vrf1:10.20.30.40,both --ipv4-uc-nbr-add-path-advertise-all 10.20.246.15,ten1vrf1:10.20.30.40,true --ipv4-uc-nbr-add-path-advertise-group-best 10.20.246.15,ten1vrf1:10.20.30.40,true --ipv4-uc-nbr-add-path-advertise-best 10.20.246.15,ten1vrf1:10.20.30.40,10 --ipv4-uc-nbr 10.20.246.16,ten1vrf1:10.20.30.40,50000 --ipv4-uc-nbr-bfd 10.20.246.16,ten1vrf1:10.20.30.40,true --ipv4-uc-nbr-add-path-capability 10.20.246.16,ten1vrf1:10.20.30.40,both --ipv4-uc-nbr-add-path-advertise-all 10.20.246.16,ten1vrf1:10.20.30.40,false --ipv4-uc-nbr-add-path-advertise-group-best 10.20.246.16,ten1vrf1:10.20.30.40,false --ipv4-uc-nbr-add-path-advertise-best 10.20.246.16,ten1vrf1:10.20.30.40,5 efa tenant service bgp peer update --name ten1bgppeer1 --tenant ten1 --operation peer-add --ipv4-uc-nbr 10.20.246.15,ten1vrf1:10.20.30.50,50000 --ipv4-uc-nbr-bfd 10.20.246.15,ten1vrf1:10.20.30.50,true --ipv4-uc-nbr-add-path-capability 10.20.246.15,ten1vrf1:10.20.30.50,send --ipv4-uc-nbr-add-path-advertise-all 10.20.246.15,ten1vrf1:10.20.30.50,true --ipv4-uc-nbr-add-path-advertise-group-best 10.20.246.15,ten1vrf1:10.20.30.50,true --ipv4-uc-nbr-add-path-advertise-best 10.20.246.15,ten1vrf1:10.20.30.50,8 --ipv4-uc-nbr 10.20.246.16,ten1vrf1:10.20.30.50,50000 --ipv4-uc-nbr-bfd 10.20.246.16,ten1vrf1:10.20.30.50,true --ipv4-uc-nbr-add-path-capability 10.20.246.16,ten1vrf1:10.20.30.50,receive --ipv4-uc-nbr-add-path-advertise-all 10.20.246.16,ten1vrf1:10.20.30.50,false --ipv4-uc-nbr-add-path-advertise-group-best 10.20.246.16,ten1vrf1:10.20.30.50,false --ipv4-uc-nbr-add-path-advertise-best 10.20.246.16,ten1vrf1:10.20.30.50,4
| efa tenant service bgp peer show --detail ======================================================== Name : ten1bgppeer1 Tenant : ten1 State : bs-state-created Description : Static Peer ----------- Device IP : 10.20.246.15 VRF : ten1vrf1 AFI : ipv4 SAFI : unicast Remote IP : 10.20.30.40 Remote ASN : 50000 Next Hop Self : false Update Source IP : BFD Enabled : true BFD Interval : 0 BFD Rx : 0 BFD Multiplier : 0 Default Originate : Default Originate Route Map : Add Path Capability : Send, Receive Add Path Advertise : All, Group Best, Best 10 Dev State : provisioned App State : cfg-in-sync Device IP : 10.20.246.15 VRF : ten1vrf1 AFI : ipv4 SAFI : unicast Remote IP : 10.20.30.50 Remote ASN : 50000 Next Hop Self : false Update Source IP : BFD Enabled : true BFD Interval : 0 BFD Rx : 0 BFD Multiplier : 0 Default Originate : false Default Originate Route Map : Add Path Capability : Send Add Path Advertise : All, Group Best, Best 8 Dev State : provisioned App State : cfg-in-sync | Device IP        : 10.20.246.16
 VRF              : ten1vrf1
 AFI              : ipv4
 SAFI             : unicast
 Remote IP        : 10.20.30.40
 Remote ASN       : 50000
 Next Hop Self    : false
 Update Source IP :
 BFD Enabled      : true
 BFD Interval     : 0
 BFD Rx           : 0
 BFD Multiplier   : 0
 Default Originate: false
 Default Originate
 Route Map        : 
 Add Path Capability : Send, Receive
 Add Path Advertise  : Best 5
 Dev State        : provisioned
 App State        : cfg-in-sync
 Device IP        : 10.20.246.16
 VRF              : ten1vrf1
 AFI              : ipv4
 SAFI             : unicast
 Remote IP        : 10.20.30.50
 Remote ASN       : 50000
 Next Hop Self    : false
 Update Source IP :
 BFD Enabled      : true
 BFD Interval     : 0
 BFD Rx           : 0
 BFD Multiplier   : 0
 Default Originate: false
 Default Originate
 Route Map        :
 Add Path Capability : Receive
 Add Path Advertise  : Best 4
 Dev State        : provisioned
 App State        : cfg-in-sync
Dynamic Peer
-----------
    0 Records
    0 Records
===============================
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