Hi Cahira,
So you need original police clearances. Appendix A is for requesting police certificates from the respective country, typically one that is not your home country. For example, I lived in Uganda for 8 months, but I am an American. I got my FBI background clearance done without using Appendix A cause they have their own process. However, for Uganda, I needed to use Appendix A because it gives them the pertinent details and requests them to send the police clearance to you. So, send that application, along with valid fingerprints, to any office that you need to go through for police clearances.
If you know the process for obtaining one in your home country (FBI check in my case), then by all means, do that and you can disregard the appendix.
Let me know if this is confusing and hopefully this helped!