The messaging feature does not currently allow you to send attachments. However, you can still use it to send links to content posted elsewhere, such as newsletters. To do so, embed a link in the message body. This requires very simple HTML code:
<a href="URL">linked text</a>
Here's an example of what this would look like in practice:
Our latest newsletter is available! You can read it <a href="https://www.website.com/newsletter/latest">here</a>.
Before you send messages with links to your providers, send one to your test provider first (see Test Provider Account to learn how to create a test provider). Then, log in to KidKare and make sure the link works properly.