How to create a To-Do from Thread

In an open Thread conversation, click on the 3-dots icon next to a chat message and select "Create To-Do"
Tap on your new "To-Do" to open up its details page
With your "To-Do" you can assign it to a member of the conversation or yourself, assign a due date, add a reminder, add an attachment, copy or move it to another Thread, flag it, or delete it.
Any changes made to the To-Do will be shown in the details page, and a message in the conversation will show up detailing who the to-do has been assigned to