I'm runnning the bitnami image on Google cloud (5.1), trying to get sms reminders working. 

Provider Account is set up and tested, extension installed and configured, but when I send a test sms it is reported as delivered by Civi, but it's not, and nothing appears in the providers reporting either, so I assume there has been no actual communication with the gateway.

How can I troubleshoot this? Does the extension work with 5.1?