log on to PAYPAL then:-
Once the relevant details are filled in, you'll need to select 'Step 3: Customise Advanced Features' (it's just above the Save Changes/Create Button, button). About halfway down, there is an option that is 'Take customers to this URL when they finish checkout'. You can then choose which URL that you'd like your customers to go to. Once you're done, click 'Save changes/Create button' to proceed. The next step is to copy and paste the HTML code in to your site. Then you're done!
Other methods include using websites like sellfy.com