You may ask if adding a hyperlink within the ticket internal note is possible in Kayako Classic. This article provides the answer to this concern.
We are sorry to inform you that the feature to add a hyperlink within the ticket internal note is currently not available and has been identified as a feature enhancement. We have conveyed the information to our product team already.
For agents, follow the Submitting a Feature Request - Agent Guide if you received such a request from a customer.