I came across this website. It contains drivers for the Novag Citrine and other computer connected chess boards.
https://goneill.co.nz/chess.php
I was particularly interested in the Novag Citrine to Fritz drivers. Look for the following paragraph.
"Fritz and ChessBase
It took me a long time to get my drivers to work in Fritz and I finally succeeded in June 2022. They need to be 64 bit and that is why they are different files to the other drivers which are all 32 bit. This means they will only run in Fritz versions 15 and above and ChessBase 13 and above (although I think 12 also had an option for 64 bit)."
I installed the software and it worked immediately.
If need help connecting your Citrine to the computer here is a link to my guide. (https://www.chesstech.info/2019/02/novag-citrine-connecting-to-pc.html)
I have Fritz 16 and am very pleased to be able to use it with the old Novag. After installing the program (Fritz-CB.dll) I just opened the Fritz program. Selected Board from the top row tabs (see picture below) and clicked the DGT board check box. The Control window popped up and the connection was made. I hope someone finds this info helpful.