Navigate to Settings > Admissions > Status & Notification, to edit the Status Notification emails.
Click on any of the Status names in order to edit the notification email.
First you will need to upload your file, in order to create a link to that file. Navigate to Settings > Pages, and click the pencil icon to Edit a current page.
Or click to + Add New Page. You can choose not to publish the page, if you do not wish the file to be publicly available.
Click the Insert File button.
Click Browse, select your file, and click Upload. Click on the filename to insert a link to the file into your page.
Right click on the uploaded file link to copy the link / URL. Paste the link in the URL area of the HTML code <a href="URL">any text here</a>. The words that you would like to appear as the link should go in the any text here part.
Then copy your HTML code into your Status Notification email at Settings > Admissions > Status & Notification. You will need to click the Save Changes button to save your email.