To add a hyperlink for a text in the email template, please follow the steps mentioned below:
Navigate to the Punchh Platform > Settings > Email template > Select the email template > Edit > Save and configure template
1) Drag a text box to the image.
2) Double click on the Text box, and tap on the link icon (outlined in red) 
3) A pop up will get displayed.
4) Add the desired URL, and it will reflect on the associated email template.
Please make sure to save the changes made.