Make sure the player is one of the conversation participants:
playerNpcConversation.png (2.5 KiB) Viewed 882 times
Set the node's Actor to the Player. (See the blue nodes below.)
playerLines.png (31.2 KiB) Viewed 882 times
Inspect the Dialogue Manager GameObject, and tick Subtitle Settings > Show PC Subtitles During Line:
playerSubtitles.png (30.15 KiB) Viewed 882 times
If a node links to more than one player node (blue node), it will always show a response menu.
If it only links to one player node, then:
If the Dialogue Manager's Input Settings > Always Force Response Menu is ticked, it will always show the response menu unless you include the markup tag "[auto]". (See the second blue node in the image above.) If the node has "[auto]", it will play as a subtitle.
If Always Force Response Menu is unticked, then it will show the node as a subtitle. If you want to force a single node to show as a response menu, include the "[f]" tag (force menu).