It's been a while since I have dealt with it but you should get a claim draw link. I think the main issue that crops up is if your opponent has a conditional move set at that time (for triple repetition) which will fire before the link is available.
https://support.chess.com/customer/portal/articles/1444798-how-do-i-claim-a-draw-
I've found in Live-Chess that if my move will make the third repetition or 50 moves, I can click on the offer draw button and when I make my move, a draw is declared. On-line chess may be programed the same way.
Note: I discovered this when one of my opponents was using pre-moves to stop me from claiming a draw after the position had been repeated. For the heck of it, I clicked on the offer draw button before I made my move.
When you repeat the position 3 times, "Offer draw" button become "Claim draw". I guess it's the same for 50-move rule.
For Correspondence Games - like this one is 7 days per move - How do you make a claim? I have a game with a myriad of instances of 2-fold repetition (2 instances of the same position with the same player to move with that player having the same legal options). Game has been a dead draw for ever. Eventually he's going to run out of moves that avoid 3-fold or hit 50 moves. When I am about to make that 50th move OR make a move that creates a 3-fold, do I submit the move, hurry back to the game, and click offer draw, and it will claim instead of offer automatically? Or is there something else I have to do? Haven't had 3-fold in correspondence on here before.