Navigation LabelAdd below code in navigation label to set call now button.
<i class="fa fa-phone"></i><span>Call Now</span> 123 456 7890
Add Class Name
call-now

Navigation LabelAdd below code in navigation label to set call now button.
<i class="fa fa-phone"></i><span>Call Now</span> 123 456 7890
Add Class Name
call-now