The following Wheelbase sections allows you to edit the text and eventually add HTML formatting text tags. However, you always need to test on making a new booking. Looking at receipt of an existing booking will not reflect the recent changes.
Custom notifications are setup by you through the dashboard and can be scheduled to trigger at any time before or after a customers reservation takes place. Make sure you add enough white space in your custom notification text to make it readable.
Some very basic tag examples you can take advantage of:
<br> line break (force a new line)
<b> Make text between tags bold </b>
<i> Make text between tags italic </i>
<u> Make text between tags underline <u>
<ul><li> bullet-point list </li></ul>
www.yourwebsite.com"> link text </a>
Click here for a deeper guide into how to use HTML tags to format text