You must create a BGP peer for the corresponding address family in order to access AWS resources that also use that address family.
When creating a IPv6 BGP peer, the Amazon address and customer address fields must be left blank. IPv6 addresses are automatically assigned from Amazon's pool of IPv6 addresses; you cannot specify custom IPv6 addresses.
For a public virtual interface, the Autonomous System Number (ASN) must be private or already whitelisted for the virtual interface.