First, click on the Messages icon at the top left.
Then click on the pencil icon to the right of Conversations list to open the form for creating a conversation.
Then, in the search bar, search for the first and last name of the desired person.
You can also add it with the buttons if it appears.
To conduct a group conversation, check the box Create group and search people you want to add with the search bar.
Finally, click on the paper airplane icon at the bottom right of your screen.
You can add a GIF or a photo in a conversation.
Finally, you can very well add a person after creating the conversation.
To manage the settings, click on the Gear icon at the top right, next to the name and surname of your recipient. A new window opens.
You can also manage your notification settings related to the current conversation for each discussion.
It's simple to send a message, but be careful not to get the wrong recipient ...