You can certainly just show the physical card for status benefits, and hopefully all works in that regard, but there is also a more sophisticated way to do this.
I believe you need an agent that can help, as they are able to access and have the two distinct FF numbers added to the relevant fields in the booking for both FF status, and FF earning. As
this 2019 article from AFF calls out, there are 4 FF fields for this type of thing that are available (as shown below). AFF member and agent/expert
@madrooster (who is mentioned in that article) would be better placed to confirm this is still possible, and your options to get it done. ISTR that one of the airline booking sites had the ability to capture both, if you could open you booking from there, but maybe I'm dreaming:
Cheers,
Matt.