In order to use TriSignup, your browser must accept cookies. Otherwise, you will not be able to register for races or use other functionality of the website. However, your browser doesn't appear to allow cookies by default.
If you still see this message after clicking the link, then your browser settings are likely set to not allow cookies. Please try enabling cookies. You can find instructions at https://www.whatismybrowser.com/guides/how-to-enable-cookies/auto.
You will need to follow this link to log into your RunSignup account, https://runsignup.com/Profile
In your Upcoming Events find the Why Not Tri and select "Manage Registration".
You will be brought to your Why Not Tri Registration information page. Here you will select "Giveaway" in the above menu bar.
You will then be brought to the 'Giveaway' management page. Where using the drop down menu you can adjust the shirt size you selected during registration. Then hit 'Continue' to complete the process.