When you log in to Il, near to you profile image there is an inbox icon if u single click on that you will get 2 options show all and start a new conversation click on start conversation, type the recipients user id and send the msg. Another way of doing this is single click the profile of the person you want to send msg to then also you will get start a conversation option through that also you can msg people. Type the user id of the person. In participant's name compose the msg and then click on the start a conversation button and you are done.