Can I display my phone number?
Yes.
You should add the following to the embed code:
<script>
let CR = {
callNumber: "1-800-555-555",
};
</script>
<script defer src="https://callbackrequests.com/embed/button.js?0.1.3"></script>
When you do this, the modal's first screen will be a prompt to call or request a callback. If someone visits the page outside your operating hours (specified in the website settings), there will be a prompt to request a callback (left below). If they visit during your operation hours, there will be a prompt to call or request a callback (right below).
