Inserting hyperlink fields into emails and tasks
When you take a sharepoint hyperlink field and put it into a task form or email, by default the value of the field is converted to string and looks like this:
Salesforce - from side bar
By default, it should take the display text of the hyperlink and build a link out of it with the URL
This idea is currently supported in Nintex Workflow Cloud. As our next generation workflow orchestration platform, we recommend customers to move to NWC. Learn more about NWC and the migration tool here.
Josh Moore commented
Furthermore, there is no way to build a hyperlink from the hyperlink field using the hyperlink button in the designer, because the properties of the fields are not available in the insert hyperlink button.