IPv6: How does one have the system use a prefix gotten from rtsol with a static host part?

From: Larry Rosenman <ler_at_lerctr.org>
Date: Sat, 12 Mar 2022 00:44:11 UTC
     I'm moving my colo to a new provider, and was wondering what the 
/etc/rc.conf looks like for
getting a prefix-delegation via my FireWall, and then using a static 
host part on the interface?

I.E., im a purely static setup, I have <prefix>::53:1 set for a host.  
What do I put in /etc/rc.conf
to use the prefix that I get from my router, but using the ::53:1 host 

Larry Rosenman                     http://www.lerctr.org/~ler
Phone: +1 214-642-9640                 E-Mail: ler@lerctr.org
US Mail: 5708 Sabbia Dr, Round Rock, TX 78665-2106