A valid credit/debit card and a verified PayPal
A valid credit/debit card is required to list, sell, and buy tickets.
A verified PayPal is required to accept payouts.
If you haven't already done so, you can add a valid card and link your PayPal account through your 'Account Settings' under 'Payments & Payouts'
If you do not have a PayPal account you will have to create one then link that PayPal account before you can list your tickets for sale.