In Webex, you get assigned a calling option that works best in your organization or for your individual needs. So, when you make a call from the app, your calling experience depends on your account settings.
You can make a call from many different places in Webex. Just look for the Audio or Video call icons whenever you're working directly with one other person, like when you're messaging them directly, searching for them, looking at their contact card, or entering their name or email address into the dialpad.
Choose whether you want to make it an Audioor Videocall and then choose Call on Webex.