By connecting to PayPal you allow your customers to pay with either their PayPal account or using a credit/debit card.
Connecting with PayPal
Go to Settings > Payment providers
Click Connect with PayPal to open up a new window that will take you to PayPal.
Log in to your PayPal account, or -if you don't have an account yet- click Sign up.
Once you have completed the setup, close the new window and return to Booqable to start accepting PayPal payments.