# OTN - One Time Notification (Facebook)
OTN(R) is short for One Time Notification (Request) and allows you to send one follow-up message to a user once they opted in for this. This is only applicable to the Messenger channel.
You will be able to create ONTR in two ways.
# Create and manage from overview
The first way to create OTN topics is by going to the contents tab on the left-hand menu, then to the OTN Topics tab.
From here you will be able to find all your create OTN Topics up till this point and you can manage them.
If you want to create a new topic then you only have to press the button in the top right corner named + New Topic. Once you press it a pop-up window will appear.
From here you will be able to name and add your topic. Once you press the button Add you will be returned to the main overview and your newly created topic will be displayed there.
You will also be able to rename the topics by just pressing it and typing in your new name for it, or delete it by pressing the trash bin icon on the right of any topic.
# Create OTN topics in the flow builder
Another way that is more direct and easy is to create the OTN topic directly inside the flow builder.
Just go to your flow then insert a Send Message block, then go to One Time Notification -› OTN Request.
This will bring you to the opt-in message of the OTN request. From here you will be able to select one of the available topics already created or create a new one directly on the spot.
Once pressed the topic will be created and you will be able to use it to request an opt-in from your subscriber.
# How to request an OTNR and use it to send the OTN message
Once you created or selected your topic inside the flow builder you will be able to draft up your own message.
Soon as the user presses the Notify me button that user will be opted in to receive one message about that specific topic.
This will allow you to send a message to the user concerning that topic outside the 24-hour window of the last interaction.