If the phone number on your site is displayed as an image, you can set up substitution by following these steps:
Wrap the img element in another replaceable element. For example:
<div class="ya-phone"><img src="my-phone.png"/></div>
On the Target Call page, click Edit number. In the number editing window, instead of the substitution macro, enter the name of the file with the image of the special number (in our example, this is the file ya-phone.png).