Here is how you can use it:
Open any direct message chat from your X iOS app.
Long press on any message that you sent or tap on the three-dot menu beside the message.
Select the “Edit message” option to modify the sent message.
According to a support page, there is no time limit for editing the messages. In our testing, we found out that you can also edit older DMs on the platform too. However, you can only make five edits overall to a message. The social network applies the same limit on editing posts as well.