Hi Hinsel,
Thanks for getting in touch and for your interest in our WooTickets plugin. Since WooTickets using WooCommerce for the payment side of things, any payment gateway that WooCommerce accepts can be used with WooTickets. The free WooCommerce product does not include PayPal Pro. However, I poked around on their site and found two WooCommerce extensions that would work for your client, PayPal PRO and PayPal Advanced. So although our plugin does not include this feature by default, the functionality is achievable with an additional add-on from WooCommerce.
Let me know if I can be of any further assistance.
Cheers,
Leah