Not every event on Tixr gives you the option to pay with PayPal. If the event you are purchasing tickets to allows PayPal you can find it on the check out screen after you add the desired tickets to cart and click Buy Tickets. 

First choose '+ New Payment Method'

Choose 'Use PayPal', log in to your PayPal account and confirm your purchase. 

*If that option is not available then it is not an option for payment for that event. Let us know if you have any further questions!*