Why cant I connect my CDJ2000's to laptop with rekordbox?

0) Have you read the "READ ME FIRST" thread in its entirety AND TRIED THE SOLUTIONS THERE before posting: YES

1) Operating System: MAC OS CATALINA 10.15.4
2) OS Type: 64bit / 32bit
3) rekordbox version: 6.5.3
4) Using LINK: YES
4b) LINK Connection method:  USB connection from each CDJ2000 to laptop and then an ethernet connection between the 2 CDJ2000's.  CDJS are connect to DJM-2000 mixer via RCA audio cables and then USB from Mixer to apple mac laptop
4c) Using with CDJs: VER 4.33
8) Is rekordbox crashing at all: No 
8b) If not crashing, are there any error messages: No 
9) Are you able to repeat / reproduce the problem: Its never worked
10) Does the problem occur with one specific song: No 
10a) If yes, please post a link to it:
11) Any other notes regarding your setup only: 
12) Provide as much detail of the issue here:

I am trying to connect my laptop to work as a controller for my CDJ2000's & DJM 2000 mixer. I have installed all of the required for both the DJM 2000 mixer and CDJ2000's and I can see the options in the rekordbox. I select the DJM 2000 mixer as the audio source but then I dont get the option to choose the CDJ2000's as output device it only shows the 4 channels for the DJM mixer. 

I have followed the instructions and read through the manual and followed from start to finish but no luck. Please help.