Cisco ASA IPV6 RA DNS announcements?

Hi

I use a Cisco ASA Firewall as gateway.

I'm trying to set up IPv6, but since Android phones does not support DHCP IPv6, it is my understanding that they need to get their DNS servers via IPv6 ND RA messages.

The problem is, I cannot see that option on my Cisco ASA.

On my Catalyst 9300 switch, the option is there, but not on the ASA.

So how is this supposed to work? How do other people with ASA as firewalls solve this?

Thanks.