The form builder should not allow you to link the button directly to your calendar widget. This allows the form submission to bypass any required consent boxes, captcha and entry of customer details. After 4 A2P denials, I realized it's not being rejected over the way the consent was worded. I learned the hard way. (If a link on the button is needed for other use cases, maybe build a separate form specifically for A2P / Consent & add the option to choose which checkboxes are required versus all or none at all.)