To do this, press the three horizontal lines on the top-left of the screen and select the ‘Certificate’ option.
Choose the machine type you are on and follow the steps on screen (including following any ‘download certificate’ links).
The instructions for installing the certificate are found by clicking the above guides which are inside Caller One itself.
Don’t forget to press the download certificate link first and then scroll down to the appropriate section for the device.
Once the certificate is all installed, you need to close the browser and open Caller One again. You will know the certificate has been installed as a padlock icon will appear at the top of the browser address bar.