Ko-fi doesn't display your email address publicly. At the payment stage, ko-fi hands over to your PayPal page.
Depending on your PayPal setup, PayPal may show your email on their 'checkout' page. It's possible to set up a new email account and associate that with your existing PayPal account. Your PayPal account can have multiple addresses associated with it.
Alternatively, you can set your PayPal to a 'Business' account for free. The name of your choice will appear on your payment page. This is the best option for hiding your personal information from donators to your page.