Yes you can.

You'll need to do it during a time that SDK is switched on. Check the activation schedule. 

Create a region where the test phones are located. Ensure that the test phones have downloaded the app and have provided location permission. To check they are transmitting data, use the heatmap.

If you don't see them on the heatmap, it may be they need to move to generate an update (especially if doing outside GPS tracking and the test phones are indoors where the GPS signal could be degraded).

Set up a test message:

1. On the Message Content tab:

   
   Include the word "test" in the message name field. This will mean any test messages are conveniently grouped under "Test messages" at the foot of the messages UI.

   Message subject and message text can be any test content. 
   
   

2. On the Schedule message tab, select "When I click send".
   
   
3.  On the "Filter message audience" tab, select the region where the test phones have been present, and select a time window during which they were present in that region.
   
   
4. Publish the message.
   
   
5. Send the message.

A successful test will result in the test message being delivered to the test phones and the number of recipients shown on the messaging UI.