Country/language for button image - Auto mode will determine the button's language based on the user's defined language for their Joomla profile. Otherwise, choose the appropriate language.
Display amount to be charged - If set to yes, the amount will be displayed above the button image. The amount dynamically updates based on user selection (if applicable)
Request an address - If you want to have the user enter an address on your site before being sent to PayPal, check this option. Upon clicking the PayPal button, a modal window will appear requesting the user's name and address. This information will be sent to PayPal.
If you do not want the user to be able to change the address on PayPal's page, change the Shipping Address Requirement field under the Checkout tab to "Do not prompt for an address."
Buttons submitted to the built-in cart will use the maximum requirement from the buttons in the cart. So for example, the cart will require a shipping address on PayPal's page if you have two items in the cart that do not require shipping and one that does.
Button images - For each button, there are several images you can choose from. Or you can choose your own image. You can either use a relative or absolute URL when using your own image.
PayPal images are retrieved from PayPal and cached locally to make for quicker loading on your site (and to prevent PayPal from dynamically recreating the image each time). They are stored in components/com_easypaypalbuttons/cache/ if for some reason you need to remove one.