Step 1: You will need to follow this link to log into your RunSignup account, https://runsignup.com/Profile   

Step 2: In your Upcoming Events find the Anchorage RunFest and select "Manage Registration". 

Step 3: You will be brought to your Anchorage RunFest Registration information page. Here you will select "Add-Ons" in the above menu bar. 

Step 4: Then you can purchase an add-on. Then you select 'Continue'.

Step 5: Then, you will be taken to the payment screen where you will see your 'Total Amount Due'. You will then enter your payment information, and select 'Confirm Payment'.