Call from the site to customers?

Question

SIP

Good afternoon. There was such a task that it is required in a web application to implement calls to customers with minimal actions for the user.
Let's say there is a table with fields (Name, Phone), the user clicked on the phone number, a new window opened with a "dialer" in which the call takes place. There will be no more than 2 users.
I will be grateful for any help.

Answer 1

skype, zingaya, asterisk, etc.
voximplant, twilio - give API