You are able to send messages to your Swarm modem from the ModuSense Portal V2.
Log into the ModuSense Portal V2.
Go to Admin > OEM.
On the far right are a series of icons.
Click the arrow pictured above.
Type your message in the box pictured below and click Send.
NB: Swarm will attempt to place the message on the next satellite that will pass the devices location, however, depending on transmission time and location of the device, there may be some delay in your Swarm modem receiving the message.