Where +91 is country code 0123456780 is demo number, You can replace this from your original number.
Below is a clickable phone link you can test. In non-phone browsers (PC and Mac desktop and laptop computers), this link may be open Skype, ask you for the application to use, may give the user an error, or nothing will happen.
Click Here To Call Support 0123456780
<a href="tel:+910123456780">Click Here To Call Support 0123456780</a>