Log in to your Store.

Go to the Products tab.

Click the Edit button on the product you would like to add the product link to.

Navigate to the product page and click Edit Options.                                                                                                                                                                                                                                                                                      

A blank text field will appear near the top of the screen; enter the link in the field.                                                                                                

Once you have entered the link, scroll down to the bottom of the screen and click the green button labeled Save. This will take you back to the edit product page.

Click Submit Product for Review and you're good to go!