You can bid for or avoid pairings from the Pairing search screen.
Before you can add a bid you must have an active Start Pairings bid group in your bid.
The blue highlighted bid indicates that it is the active bid group (highlighted by red box in the screenshot). Click on the bid 1, Start Pairings to highlight the entire bid group. If you have multiple Start Pairings bid groups the bid is entered in the active one below the highlighted bid.
The inactive Start Pairings bid group screenshot shows an inactive Start Pairings bid group. The first bid in the Start Reserve is highlighted blue (shown with red box).
The following error message is displayed if you attempt to add a bid without an active Start Pairings bid group.
Your current bid selection is not compatible with new Award/Avoid Pairings Bid Preference. Please adjust your selection and try again.