At this time, it is not possible to "post anonymously" when logged in. You would have to enable the "reply to topics" privilege to a specific category for guests, and then your users would need to log out to post as a guest.

@Trishla-Verma-0 said in Anonymous replies for registered users: A checkbox near the text area which when ticked will lead to the post/reply being anonymous. This is different from the guest functionality as only logged in users can use this function. Good idea I hope this is possible and somebody will make this