If you have a participant that declined their waitlist invitation or was removed from the waitlist some other way, you can add them back and reissue their invite to register.
*** When a runner declines their invitation, you must add them back to the waitlist if they need to reregister.
Open your waitlist by navigating to registrations and then dashboard, click on the hourglass next to the distance that the runner registered for originally:

Next, scroll to declined invitations, and click ‘add back’ next to the runner’s name:

Refresh your screen, and the runner should appear under ‘Waiting for the participant to respond’, and longer under ‘declined invites’

Then click ‘Resend invitation’.
Your participant can then respond to the invitation to complete registration.