You can link a PayPal account to your StubHub account directly from your profile or at checkout.

From your profile

1. Go to 'My tickets' then Settings. The 'Payment' tab is automatically open. On the StubHub app, tap 'My tickets' then the first drop-down menu to select 'Settings.'
   
2. Under 'Payment options for buying tickets,' click the trash can next to the PayPal account you want to remove
3. Click 'Add New Payment Option,' select 'PayPal,' and follow the steps to link your account
   

At checkout's 'Review and Buy' page

1. Click or tap 'Add Payment'
   
2. Choose 'PayPal'
3. Follow the steps