Unfortunately, it is not possible to edit your primary email address as it is the one you used to register for the event. However, you can add a secondary email address you have access to to to log into the platform.
For this, go to My Profile > Settings (https://app.swapcard.com/settings) and click on Add an email address under the Email addresses section. Enter your secondary email address, click on the Add button, and then go to your inbox to confirm the newly added email address. Once confirmed, you will be able to use any of the confirmed email addresses listed to log in to the platform.