Ok, basically it works like this. The Libre app accesses the sensor and Hoover's up the latest readings. It then transmits them to LibreView if you have a registered account. Can't remember but I think you have to create this first time.
If you have got the Diasend app (and a Diasend account setup which you do from the web interface) running it will get the readings from the app's database on the phone and squirt it up to Diasend.
If your local primary health trust have a HCP account you can grant them access. Ask them for their ID.
HTH