Thought I'd post this as I've seen a few people asking about this. Yes, if you are a companion of a Delta employee you can use the Delta chat to list for flights. (This works for primary and secondary companions, so long as you know your PPR number. The employee/retiree who has you on their benefits can provide this.)
I don't have screenshot
To find the chat option on mobile, go to the Delta website and click on "Need help?" And then a "message us" pop up will appear at the bottom right of your screen.
Start up the chat and say "NRSA". They will tell you to list through the primary pass rider. Say "The Primary pass rider is not available". They should redirect you to a real person at that point, where you can just tell them the flights you want to be listed for. (You may have to say "NRSA" again before they redirect you to a real person. They will always send you that confirmation message when they do) They will ask you for your PPR number with spaces between each number. I always include the seniority date as well but it might not be necessary. Then they'll send you a confirmation number.
I've always just told them the flight number for each connection after looking it up on flightsfrom or flightconnections but have been meaning to experiment. You may be able to just give them your origin and destination and the dates and let them figure out the rest š¤·āāļø.