Right, we've updated their receiving zap address to their new Coinos wallet LN address, but Coinos isn't in the dropdown list under Zaps wallet selector.
Discussion
Click on coinos home icon then the gears icon on the right. That lets you copy the NWC string
I see same problem with Yanihonne. The drop down with wallet options is limited. I started on Amethyst and maybe I'm mistaken but I'm sure I just added my blink address (a wallet chosen at random). Easy onboard. KISS especially on an open network.