Each phone has a VoIP extension line setup on that phone - if you wish to make calls from a phone using Click2Call you will need to enter the extension number of the line you wish to make calls from (that line must be registered on your phone) inside the Click2Call extension field which is found inside the Settings icon of your CRM account. 

Here you will see a VoIP Click2Call field as shown below where you will need to enter your VoIP extension line into this field. 

For instance if working from home you may be on the 'correct' Click2Call extension line but if working from your office you may need to enter your 'other' extension line into the Click2Call settings to be able to make outbound calls from your office phone. 

As an alternative to the above option we can offer a Click2Call toggle button which we can set up to allow you to switch between different lines please click here to see more about adding this option.