For those who offer Cameo Direct, you can send one right from their profile page. Just click on the “Direct Message” button. You can see which talent offer Cameo Direct on the site (check out the “Send a DM” category) or here: https://www.cameo.com/tags/direct-messaging.
Cameo Direct is only offered in the app, though, so make sure you've got that downloaded to your device. You'll be prompted to download it if you click on the "Direct Message" button on the website :)