To set your Tel, Call To, and Votel provider in Crelate you can go to the Settings> My Settings & Preferences and then select Advanced Configuration Settings.
In order to use these providers you'll want to ensure you have downloaded the extension from the web-store. You can find that extension by searching under this link: https://chrome.google.com/webstore/category/extensions?utm_source=chrome-ntp-icon
Once you've selected "Advance Configuration Settings" you can scroll to "Phone Protocol." This will allow you to select which call provider you'd like to select as the primary. This will pull in your provider and allow you to place a call. If you're utilizing Skype, Ring Central, or 8x8, you may select the below menu. For all others, you'll want to utilize 'tel (default).' After making this change, please save and refresh your browser.
Once that has been selected, you'll be able to select the phone icon from their contact record in addition to several other screens.