Hello @IsabellR ,
When you setup a ticket for your event, you choose whether or not you'll be charging for it. Then, later in the event setup, you select the online payment you want to utilize, and connect your existing account with the payment processor to the event. When a registrant selects the ticket during their registration, they will be prompted to enter payment info to pay for the ticket and complete the registration.
See also:
Events 2.0 FAQ
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