zingaya

Zingaya enables voice calls through any computer, right from a webpage. No download or phone is required. Zingaya offers this seamless voice calling capability to website operators – whether it’s a huge e-commerce enterprise or a startup company. Simply embed a “Call” button into your website. Visitors can click that button and the call is immediately forwarded to your landline or mobile phone. All you need is a website; all your visitors need is a browser and microphone. It’s that easy.

Zingaya Click-to-Call

Let your website visitors call you. Without a phone. Zingaya enables voice calls through any computer, right from a webpage.

lizefield

You can use WebRTC simply on WordPress. 
This WebRTC is SFU mode.
This plugin loading javascript from external site. (<code>https://cdn.webrtc.ecl.ntt.com/skyway-latest.js</code>) 
Because it’s need to webrtc. 
This plugin is not Skyway official. 
This software includes the work that is distributed in the Apache License 2.0.

Skyway WebRTC

You can use WebRTC simply on WordPress. Just one tag. SFU mode.

Zingaya Click-to-Call vs Skyway WebRTC